Account paid in full: won't close account

My loan with DirectAxis was settled as part of a consolidated loan payout. Although I can clearly see on my FNB profile they received the monies and receipted it. When I ask them to please write off the interest as per the settlement keep asking for the proof of payment. Not only that but must reflect the bank and and and.

They also were rude enough to debit my bank account their usual debit order.

I think they do this on purpose to milk more money out a person than what they due.

DirectAxis is slow and painfully tedious when it comes to this part of handling accounts. I have several times dealt with DirectAxis and each time the wind up of the account is painful.