I've been trying to get help to Telkom but no one is willing to help, i call and go to the branches but the service is very bad

I bought router over the phone call is it a contract and they deliver it, the router and the simcard is not working since it was delivered, I've been forced to pay for it, i go to the branch, i did some phone call there not willing to help me, but i have to pay for it, they even threatened to sue me i dont pay within the next nex 2 months, im scared i never have a problem like this before, please i need a help I WILL BE HAPPY IF YOU CAN HELP ME