Accepting them how?
Do you gave a terminal compatible with Apple Pay?
Did you setup the payments with the card issuers and banks to process them?
Or are you referring to receiving payments via Messages?
Why did it take you so long to realize you were to getting payments?
For any payment made through Apple Pay, the transfer of fiund would be between you and the card issuers, Apple has nothing to do there.
If you were receiving payments via Messages, then Apple Pay has nothing to do with that. Its a direct money transfer, and it does not go to your bank account directly. It would be in your Apple Cash account if it was accepted, or would have been automatically declined if you did not actually accept it, or have no Apple Cash account to receive these payments.