Keep paying my closed account but the amount outstanding remains the same.

im not shure how this works im trying to finish my account but they keep on sending me sms es everyday charging me for it calls that they charge me 20 rand a call what for i dont know cos im paying everymonth. i increased my debit order and still i almost ow them 2000 rand this is freeking rediculous realy. my ammount should of been much less by now. i will never open or recomend any one to open an mr price account.