MTN Horrible Customer Service

Absolutely poor customer service. It is shocking the level of customer service. I cancelled my home WiFi due to relocation and returned the WiFi router. The store accepted everything and sent me a balance that I should settle which I did. A month later I get charged R5000 for the router which they say I did not return. Went a few times to the store and they confirm that I don’t owe anything and all they can say is sorry. 2 months later and many visits I still get a charge of R5000. Is shocking that major companies like MTN show so little interest in customer service. MTN don’t realize that the ship is sinking or maybe they do hence the lack of interest in customer retention.