De*****ing customers

After taking out a contract with them I soon realised that I am paying way more than I should. I soon realised that they overcharged me with almost R20000.00 rand in a period of 6 months. It took me more than 8 months to get my money back from them. When the time came I cancled the contract Nov 2013. Now 2 years later I am blacklisted for R1495.00. Phoned them And they cannot provide me with the relavent docs to prove what the monies are for. Whent to their offices only to be met by the same incompatance. I just paid the bill so that I can clear my name but while doing so was met by another customer with the same problem. When I put it on Facebook another 2 incidents of the same nature came up.