Blacklist on ITC for a contract cancelled

I went to the bank to take out some facilities, just to found out I have been blacklisted!!! For a contract I cancelled! The router and contract and the whole transaction was reversed, and now blacklisted!! Previous review: To whom it may concern, please help! We took out a contract for a Wifi Router at Cell C on 01/07/2017. First we could not connect, then after 3 days we phone to cancel. They said someone will phone back within 2 days and gave a reference nr: ********** 343. No one phoned. We phoned again. They will come out to see what is the problem. The problem is, we live in a small town called Hoopstad, Free State. There is only 1 network tower, which means the Cell C router won't work here. We didn't know it when we bought it. Everytime I phone in to follow up on the cancellation, they say they will come back. In the meantime I have to pay that premium every month and cannot use the router. I did phone within 5 days to cancel, no response. Once they said they phoned, but I didn't answer, that is because they phoned the router's number. The router won't answer. Account number with Cell C: ********** 60 / Incident: 170 ********** 00 I am not going to pay this account, and I am not willing to get blacklisted for poor service. I am willing to courier the router and whole package back, but do not know whereto. Please help.