Accounting sucks

I have got a top up contract with them on a data bundle for R214.42 pm. Last month I got an account for 1906.30<br> I went to the store and logged a complaint with them - as from that date I unplugged it from my router.<br> This month I got an account for R 5272.07. It's been almost a month ago from the first visit - and no response.<br> When I went there last Tuesday there were 2 other customers complaining about the same mess in the accounts.<br> I tried to phone head office accounts and did not manage to speak to anybody as I was cut-off 4 times.<br> I want to stop my debit order as they are deducting the money from my account.