over billed

I recently upgraded my Telkom mobile contract and frm the first month it has been a nightmare. I took up a contract that was supposed to cost me R199 a month but instead 1st month after the upgrade i was charged R805.23. I immediately quiried this(***) but was given an explaination that made no sense at all. then beginning of Jan I received another invoice stating that I will pay R548.00 end of Jan 16, needless to say i complained about this as well and was told it will be fixed and I will only pay the agreed R199 but to my surprise I was debited R548 even though I was assured that I would only be charged R199. I have been sent from pillar to post regarding this issue and i am even prepared to pay up the whole contract amount and move to another service provider.