Unhappy customer

DSTV, what have I done to you guys? You guys honestly make me regret choosing you as my internet provider, I had stopped using Multichoice for some time and now they make me regret returning. Last month's debit order didn't go through on the usual date, couple of days later I called to check how much I owed and was informed that I owed R620 (stand to be corrected), which I paid R640. On my debit order date this month, R968 was debited instead of R779. And now I'm told about the monies that were not there last month, some charges that I have never been charged for. If you see my previous complaint, I stated that since signing up for DSTV Internet I have been having problems with them almost every month; and when I want to terminate my contract with them because I believe they failed to fulfill their obligations on their side, they say I can't. Maybe it's time I take this further because I'm not happy with this whole thing as it's a nightmare.