How to recover iCloud account and unlock iPhone after forgetting password?

Customer care was wrong to have you raise a "complaint" here, or you just misunderstood them. The people on this forum are just other customers like you.

You say the account is locked, but there are many types of locking for different reasons. From what you say this is one possibility: ● If your account has been disabled for “security reasons” the solution is to reset your password as outlined in this document: If you forgot your password and can’t sign in to your Apple Account - Apple Support

If you find you can’t sign in, reset your password, or receive verification codes, you can request account recovery (read this support article: What to expect during account recovery - Apple Support ) to regain access to your account. More detail in —> Activation Lockout Issues - Apple Community For additional assistance from Apple Security, read: Contact Apple Support - Apple Support

As for the iPhone, again there are different types of locking/disabling, but you have not told us exactly what it says. Here are some possibilities and solutions in the support articles:

If the iPhone says it is "disabled":

If you forgot your iPhone, iPad, or Apple Vision Pro passcode, reset your device without a computer - Apple Support

If you see "Activation Lock":

Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Read the requirements and steps for an Activation Lock support request at: https://al-support.apple.com/#/additional-support and links at the bottom right for the type of service requested. Apple says they “may” require "proof of purchase documentation” and that you need “proof of ownership documentation”, but does not detail what currently constitutes proof other than it “must include the product serial number, IMEI or MEID.” User reports on this community and chat with Apple indicate that typically Apple will absolutely require, and ONLY accept, an original receipt issued by Apple or an Apple Authorized Reseller. Presumably this is the only kind Apple can authenticate against fraud since Apple is not involved in third party sales. Apple recommends that you "Keep your receipt after you buy an Apple device" --> Keep your receipt after you buy an Apple device - Apple Support

Note that the device cannot have Lost Mode set on it or be a managed device.

If anybody tells you that you have to be the “original” owner, they are wrong. In the case of removing the lock with the correct information, it can be anybody who knows the currently signed in account information. In the case of asking Apple to unlock it, as long as you have the original Apple receipt (which may well not have any personally identifying information on it) you are okay. Apple confirmed this in a conversation.

Welcome and thank you for reaching out. 🤗

According to Apple:

Use a trusted Apple device:

The easiest way to reset your password is with your iPhone or other trusted Apple device — one that’s already signed in to your Apple Account, so that Apple knows that it’s yours. You also need a passcode (or password on Mac) set up on that device.

Resetting your password on the web when you don’t have a trusted device is another way to regain access to your account.

Reset your Apple Account password on your iPhone, iPad or Apple Vision Pro:

1. Open the Settings app, then tap [your name].
2. Tap Sign-In & Security.
3. Tap Change Password.

4. Enter your device passcode.

Then follow the onscreen instructions to change your Apple Account password.

You might be required to wait one hour before changing your Apple Account password or other critical security settings. Learn more about Stolen Device Protection and when a security delay might be required.

Reset your Apple Account password on your Mac:

1. From the Apple menu , choose System Settings.
2. Click [your name], then click Sign-In & Security.
3. Click Change Password.

• Enter the password used to unlock your Mac. Then follow the onscreen instructions to change your Apple Account password.

If you’re trying to sign in on a new Apple device:

If you’re not signed in to your Apple Account on an Apple device, you can select “Forgot password or don’t have an Apple Account?” during device setup on the Apple Account sign-in screen.

If you skipped signing in during setup, you can reset your password in Settings:

• iPhone or iPad: Open the Settings app, then tap Apple Account. Select “Sign in manually”, then tap “Forgot password?” and follow the onscreen instructions.
• Mac: From the Apple menu , choose System Settings. Click Sign in, then click “Forgot password” and follow the onscreen instructions.

If you don’t have a trusted device:

If you’re not able to use one of your own trusted devices, borrow a device from a family member or friend. You can also change your password on iforgot.apple.com.

Reset your Apple Account password with the Apple Support app on a borrowed device:

If you don’t have an Apple device but have access to your trusted phone number, use the Apple Support app. You can borrow an Apple device from a friend or family member, or use one at an Apple Store.

1. Open the Apple Support app on the borrowed Apple device. If you need to download the Apple Support app, find it in the App Store.
2. Scroll down to Support Tools, then tap Reset Password.
3. Tap “Help Someone Else”.
4. Enter your Apple Account email address or phone number.
5. Tap Continue, and follow the onscreen instructions to reset your password.

Any information that you enter won’t be stored on the device.

Reset your Apple Account password on the web:

You can also regain access to your account by resetting your password on the web. When possible, the web browser redirects you to a trusted device instead.

The reset process on the web might take a little longer. If you’ll have access to one of your trusted devices soon, it might be faster and easier to reset your password at that time.

Reset your password at iforgot.apple.com

If you need more help, contact Apple Support directly.

Thanks again for reaching out. 👍🏼

Good Luck! 👋🏼😉

Smiliñ 😎 Brian | Community Volunteer