MTN offers less than zero customer service!!

I returned a phone to MTN in Mall of Africa in January 2021. After a year of struggling with MTN the contract was eventually cancelled. For that year I paid for the returned phone as I have a second phone also with MTN. To date no one is getting back to me on refunding the amount I paid or crediting that amount to my current contract. Email after email and phone call after phone call (which all eventually got killed before resolution)