Telkom router contract

Canceling a yelkom contract is a problem. When you go to rhe shop they tell you that they only deal with sales. The always send me a link which is not working. When I call they say I should do ot online using the same link that is not working. Now they say I owe them R3000 for a service they never rendered. The suspended my service as soon as I stopped paying because the contract ended. Now they have the audacity to say I owe them. I don't know how to cancel even now.