RIDICULOUS SERVICE FROM MTN

I have canceled my contract with MTN towards the end of January as the signal in my area was so weak that I couldn't connect to the internet. I canceled this contract within my 7day trial period and was told that MTN at Ferndale ON Republic will handle the cancelation. The gentleman working there send multiple emails with regards to my cancelation and no one from MTN customer care or their cancelation department ever bothered to respond. I received a call from MTN customer care last week and the lady there told me that my request will be denied due to MTN not following their own proper cancelation procedures. I will not pay this account as I have canceled this contract and everytime I try to phone customer care or any number to do with MTN I can't get hold of anyone. Now I'm getting threats of my credit being affected because these guys can't their jobs properly.