account settled but still being charged

My mom had a Game account card which is managed by RCS. We got tired of Game/RCS always loosing her pmnts & worked it out 2 b cheaper2 obtain a loan & Pay Game/RCS off than pay mnthly. 23/05/2014 we went into Game bellairs centre & requested a settlement figure. We were advised to go to the cashier & obtain a card enquiry, then current bal is what we owe. We also asked the Game/RCS acc person inside Game if there r any costs involved if we settle & leave account open, she stated no the only time there r costs involved is when u use the acc & there is money owed. please see below for amounts pd ect. As per PLC card enquiry 23/05/2015 Current balance: R 12,627.61 Credit available: R 2,372.39 Payment due: R 1,548.60 Therefore I pd R 12,627.61 to clear the acc despite the previous statement dated 10/04/2015 - 10/05/2015 stating that out bal was R 12,605.73.I then sent the proof of pmnt to pop@rcs. My mom has received numerous msgs threatening to hand her over for a bal between R100-R288. Today she was advised the balance is R300 due to account fees of R30pm. Account was settled 4 mnths ago so hw cannhe total equal 10mnths of fees? We cleared the acc in may so how can we still owe money