You could locate that payment on account and refund it back to the bank for exactly the same date, thus reversing the original £50 Debit. Then add another £50 debit and tag it as a transfer to the credit card account.
You could locate that payment on account and refund it back to the bank for exactly the same date, thus reversing the original £50 Debit. Then add another £50 debit and tag it as a transfer to the credit card account.