Very very bad service!

There we're a misunderstanding on my account a couple of months ago. I usually pay R149 every month for 2 Gig data and all off a sudden they debited my account with R2300!! I phoned to say that there must be some mistake, but according to them that was the data I used, EVEN THOUGH I PHONED IN LAST YEAR TO CAP MY DATA USAGE!! As expected the recording of that conversation was just missing and they weren't interested in making any kind of arrangement. I told them well in that case I just want to make payment arrangements. I probably phoned 20 times, and every time it was the same story: \We cannot make payment arrangements if your balance is 0