Unsatisfactory Customer Service

On the15 August i settled My 2personal loans and Fnb was supposed to refund me the money which they debited for that month.to my suprise the refunded meR 2050.17and for the second Loan they refunded me 883 instead of R940 plus R450 which was additional to the first loan. I went to the branch and call them(call centre) they promised to look into this matter but they didn't i went there about three times with no help the last time they said the Supervisor will call me till today its three weeks now.my Account Numbers is as follows 1. ********** ********** 714 2. ********** ********** 0714.i feel that i was treated unfairly and the staff of the bank(call centre) they are pathetic and inconsiderate and that kind of conduct damages the name of the Bank and i stronly suspect that this malpractice is a norm within this division and many of us poor and vunerable are victims.