*****ing and pathetic service

I had initially taken out a contract with Telekom for a sim only deal and have been notified only after I activate the sim card will my account be active, upon going to the store to activate it I actually went to cancel the contract which was done. To date I have been billed for this and have therefore put a mark on my ITC lowering my rating drastically, I am therefore ****ed off with Telekom and there pathetic service towards me as an individual and would not recommend any1 changing to this network. I have tried to call them to resolve this many times but haven't had any response on all attempts, I have also registered on their website to sort this out and it shows that I don't have any active accounts with them so how the hell am I being billed for something I never used. The amount is quite high and I refuse to pay this as this is not my fault. Please I would require some sort of assistance with this and will definitely be taking this matter further as this is *******