Incorrect Billing

I have Had DSTV extra view since December 2014. Every month my statement shows the same amount and that the amount i pay. Since the start of November 2015 every week they disconnect my DSTV. The 1st time i phoned , with no questions asked they reconnect me. 2nd time the same no problem. 3rd time the consultant tells me that i have been short payed in October. I know am outstanding R473.18 plus my subscription of R399.00 which totals to a lot of money. i explained that i just paid what the statement said and if the outstanding showed on the statement it would be different. The only explanation they can give is they sorry and theres nothing they can do i need to pay