Cell C Incompetence

I had a 2 year contract which came to an end 31 July this year at R513 per month. On 25.06 i entered into a Top Up contract at R149 per month [20GB - 10 day time and 10 night time. This is paid by my Master Card. However, on 3rd August my card was debited with R477 and then on 2nd Sept R401,98, In response to the 3rd August debit I sent an email and was informed I should visit their branch and take my contract, which I duly did and after more than an hour, I was assured that this matter would be sorted out. However, here we are again. I have had Cell C contracts for a few years and this is not the first time I have had problems with them. However, one hopes for the best - at the moment I have 2 contracts, one entered into by phone last week. When will I learn that once a company is ***********, there is no hope. I just hope they will see this complaint and reverse the charge as I was assured by the branch by Cheswen last week.