Mr Price please explain

Good Day Mr Price I have sent a email to the Mr price team asking about this they said they will look into it but i never got an response. My account was 5500 but was reduced to 3500 because of a issue i had about 3 years ago but has been sorted out for a long time since then. I have paid my account every month sometimes late but it still gets paid with in the month. Here is my question the account generally is 6 months to pay. i pay 815 Rand every month. By my calculations for 6 month it should only be about R600 a month. I pay R815 but quiet unsure where the rest of the money is going your fees are not that much. I have cancelled all the extras and you told me I don't qualify for that anymore. This is fine but why am I still paying such a big installment on a small amount. There was a stage where my account was paid off last year for a time but for some reason i still had to pay R120 a month ...For what? please explain to me why i am paying so much into my account because i still dont understand it. This extra money you making off me is for what?