Sick and tiered of MTN! Disgusted!!

I went for an upgrade on the 01st of October 2014. I also then app**** for a Wi-Fi contract which took them several days to finalize. Once the Wi-Fi contract was finalized I got the modem but it was not working, finally they told me the simcard was not activated and same was only activated on the 21st of October 2014. At the end of November I got the billing for my cellphone contract and where the package I chose amounts to about R480 a debit order went off of almost a R1000. I was at MTN at least once or twice a week hearing the same story over and over that they will sort it out. In December again a debit order of almost a R1000 went off my account. I then went through my cellphone statements and saw that they have been charging me for BIS since my upgrade and I no longer even use a blackberry I upgraded to a Samsung. I Took my statements to MTN and told the manager that this is unacceptable and that I want my money back and that the statements does not count up to the amount that goes off my debit order. It has been more than three weeks since I gave them the statements and NO ONE has came back to me ever since! Worst service that I have ever received!!!