Game Stores Refusing to close the account

On the 27th of July I went to Game Stores Bel Air to settle the account and close it. We then phoned the call center where I was given a settlement figure of R7340.52, which I paid by the tills. I later phone RCS the following day to request a paid up letter, then the consultant assured me that she will send it through however it will take 35 working days for Game to close the account. To my surprise when I opened my emails today I found a statement stipulating that I owe R54.83. Under what grounds was this calculated as I had settled the account? I am very furious and I feel that I am not treated fairly as I had settled and closed the account and now interest as well as insurance is now charged on the account. Close the account immediately and send through the paid up letter, also adjust my information by the credit bureau.