There are no good answers for this.
The workaround that I can suggest is to do a journal entry, That debits the customer and credits the bank. For the purposes of the customer ledger, use Invoice as the document type, you can't use the same invoice number but if the invoice no. was 12345 then enter 12345. the '.' makes is unique. The Customer should be the Account Type and No. with the Bank Account Type and No. being the Bank. You will end up with debits and credits in the bank ledger. You could do a bank rec where the statement amount is the same as the GL account, and just clear these offsetting entries so you don't have to deal with them at the next regular bank rec.
As I stated, not a great answer but it will get the job done. No impact to P&L, Bank gets corrected, AR gets Correct and payments received from customers can be applied without too much trouble since the invoice numbers are virtually the same.
