MTN and Mondo are the worst.

Worst experience..I regret taking a product from MTN. I got a router from MTN via Mondo. Mondo sold me lies. Router was not unlimited and did not get network coverage in my address. I returned the product on the 11th of July 2022 within cooling period. MTN still sent me a bill of R656.46. How am I expected to pay for something that was not what I wanted? Something that I returned within the cooling period. Now MTN is threatening to blacklist me. Iam gatvol with MTN. I returned their product and cancelled it. When I call them they tell me that their warehouse is waiting for Mondo to call them, Mondo tells me another story. I have done my part. I returned their useless product. Why should I have to pay for their incompetence. It was my first time dealing with MTN. I can promise you this is my last time. My credit rating will be affected because of incompetence of this two organisations.