You are up against the banking regulations enacted by Congress that banks are required to follow.
- Bank Secrecy Act
- US Patriots Act
- SAR's (Suspicious Activity Report)
Specifically for the SAR, it is illegal for any bank to even recognize the existence of SAR that is filed or any reason that would have caused it to be filed Apple is not a bank and has no part in any of the decision making.
No bank, and no director, officer, employee, or agent of a bank that reports a suspicious transaction may notify any person involved in the transaction that the transaction has been reported. A SAR and any information that would reveal the existence of a SAR, are confidential, except as is necessary to fulfill BSA obligations and responsibilities. For example, the existence or even the non-existence of a SAR must be kept confidential, as well as the information contained in the SAR to the extent that the information would reveal the existence of a SAR.
https://bsaaml.ffiec.gov/manual/AssessingComplianceWithBSARegulatoryRequirements/04
You are free to do your own research on the Bank Secrecy Act and the US Patriots Act. All that you will know is that your account has been locked/restricted. The person you talked does not even know why as the bank does not even give them that information. It is against the law, and is not the policy of any particular bank. As you can see from doing your own research, there are many reasons why that could happen and in your case it will not be known. Many examples can be provided, but no one will know if that is the case for you.
For example, failure to identify the customer known as the Know Your Customer (KYC) section of those acts require positive identification. There are no second chances if the information that has been provided is wrong. It may not even be an issue with your account and could also be due to a transaction with another party that resulted in a SAR report that has now involved you.
Unfortunately that is the way our banking system works, you are free to contact your Congressional Representatives as to the fairness of those laws that they have passed. Only Congress can change the laws in our country.
