Mtn
Uncapped Internet doesn't work!

I have an uncapped Internet account with MTN. I pay this account and in return I expect working Internet, but instead I have a line that barely ever works, and when it does it runs really slow, like 20kb/s slow. When I've contacted them they tell me that their 3G towers are down, but my phone's 3G works perfectly. MTN has breached the contract because I am paying for a service that is not working properly, I am not getting what they promised. All I want is to cancel my contract, and not have to pay for it anymore, so I can get working Internet from someone else!