call the Bank!
if you used the incorrect banking number, it is possible that the Bank simply sent the payment back to the IRS. You don't state whether you were a digit off or not on the account number, but for many banks the last digit of the account number is a 'check digit' - unless all the other numbers are correct, the algorithm won't match that last digit, which makes it unlikely for a check to be deposited into the incorrecft account, even if only 1 digit off from your's.
