being debt for their mistakes

I took a contract with cell C via their call centre. the sales agent put me on the wrong package. I did query this and was given a case number it took them 3 weeks to sort out with no feedback from them. I was put on the right package, there after on the 26th of last month was debt R5125, I reversed the transaction, called to query my bill I was told it was cancellation fees. I made my case to the billing department and they logged a case***) I've been calling through the pass 3 weeks with no feed back. but I've been getting calls from the billing department to pay my account of R5125. they debt me on Monday(R5000) and my account is gone R.D. but yet still no feedback on the added charges on my account. I'm actually tired and frustrated with calling to ask for feedback. their customer service is very poor.I would not advise any one to use their network.