Yes, it is a scam. Apple never sends any such message and the number is not linked to Apple at all. There is no such thing as an upgrade deposit. What they are trying to do is get you to call the number and give them your Apple Account Password or Financial information to compromise your accounts or simply get you to send them money that you will not be able to dispute. Apple Cash is a private transaction between 2 parties and does not offer the protections provided by a credit card purchase. Sending Apple Cash is done to only people you know, not strangers.
You can simply delete it or report it to Apple with the information in the link below.
Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support
A word of warning is that using Apple Cash for business is a violation of the Terms of Use and could possibly result in your account being locked. You are not sent a message like you have seen above, you will just no longer be able to use Apple Cash.
- The Services may only be used for personal, family, household, or non-commercial purposes. You may not use the Services for business or commercial purposes.
https://applecash.greendot.com/termsconditions/
