Useless department called RETENTIONS

Worst service ever, I have been communicating with this company for more than a month now via phone calls and email to retentions with no joy. I have been billed a contract amount also a month to month service amount for one contract. I am now failing to make payments as my bill has increased from R629 to R867 for 2 months now and no one, I mean no one is willing to assist, how difficult that can be? All you know is to tell me about a cancelation fee when I say I don't want the contract anymore.