Part 1 of 2
The key point is that if you are buying CleanMyMac through the Mac App Store, the phone number should be part of your Apple Account billing information, not something you need to invent a special format for at the CleanMyMac checkout.
On your iMac, open System Settings >> your name >> Payment & Shipping and check that the billing information associated with your card is correct.
Apple also provides the same payment-management facility through App Store >> your name >> Account Settings >> Manage Payments. (Apple Support)
Apple accepts Apple Pay, most credit and debit cards, PayPal, and Apple Account balance for App Store purchases. (Apple Support)
If your card and billing information are already correct but the CleanMyMac purchase still rejects the telephone number, I would not keep trying different formats.
At that point, the useful thing is to identify whether the purchase is being made through Apple's App Store or directly through MacPaw, because the two payment systems are separate.
Part 2 of 2
Any third-party applications that interfere with the normal operation of the operating system are an invitation for disaster.
Certain applications may be available on the Apple App Store, but this only indicates that the developer is prepared to pay Apple a percentage on each sale.
The application’s potential impact on the computer is up to the user to verify before purchase.
Any of the following should be removed as per developer instructions:
CleanMyMac, also known as “BrickMyMac”
The above link is page 1 of 575 pages, each containing approximately 20 postings.
This means there are about 11,500 instances related to CleanMyMac and its potential impact on the computer.
While we cannot determine the appropriate course of action, we can caution you against reinstalling BrickMyMac.
