Disgusting after service and attitude

last month MFC took the wrong amount on the debit order and a supplier that is paid by MFC has not received their premium. When MFC was contacted i was advised they had system issues and a manual debit was done but no one can tell me why the wrong amount was done and the staff and managers attitude is o well sorry for you but you owe the money and finished and i am sorry i am not accepting this attitude as we pay the debit order every month without fail now because of a MFC fault we are been hounded like dogs and no one wants to help.

Please can someone contact me for the full story as i am very upset on the outcome almost a month later and still no resolution