What Contract???

I had a 2 year contract with Telkom. After the 2 years the contract was done and we went on a month to month basis. A few months after that, we get a call from Telkom saying that in our area there is alot of cable theft, and we need to get a wireless router or we won't have internet anymore. I asked if there was any extra costs or changes that would be involved, and I was assured that there are no costs or changes involved. After another few months our area got fibre and we decided to go with Afrihost. I cancelled my services with Telkom ***. And now I am being billed for penalty charges etc, Apparently when I agreed to the new router, I also "agreed" to a new 2 year contract. How does that work? How do you agree to a contract that you were not even aware of??? I have lodged alot of complaints, sent numerous emails and phoned more times than I can count. I am always told to speak to another department, when phoning another department, they can also not help me. I am not going to pay for breaching a contract that I NEVER agreed to in the first place. Telkom can come and collect the router. Telkom is never seeing me again, and I will make sure that EVERYONE knows about their sneaky ways.