Inefficient , poor service , ***********

I requested my settlement letter from first national bank to close off a personal loan a bit earlier to ensure I have better credit availability .when i went to make the payment with the amount they had sent me on a formal settlement header ,they had added more funds and mentioned I should settle more etc .I then went into the bank with the original settlement letter sent and they arranged telephonically that I was able to settle the account as it was within the 10 days agreed .the outstanding amount of 1600 and odd was agreed to be adjusted due to the error on their behalf and it took 3 phone calls and a visit to the bank to rectify , my loan was meant to be closed off as emailed from Fnb and an agent and I should be loan free yet on the 28th of this month Fnb deducted the loan again and charged me interest on a account that has been closed . This angers me as a response turn around time was said to be three days and the urgency is not seen by the loans department or the complaint department as more than 2k was deducted , I have had numerous problems with efficancy with this bank . It’s honestly poor service as a response , errors and my other accounts have bounced which has caused me to be inconvienced .