MTN Arrogance and no responsibility to customers

Purchased an uncapped service from MTN in 2022 which never worked. Eventually got a technician out after months of wrangling in April 2023 and MTN conceded the tower was incapable of delivering the service. MTN technician wrote a letter to MTN cancellations and told them this, to cancel the service, and refund, Had to hand in the modem. MTN kept billing me until May this year and charged a cancellation fee - unbelievable. No success with branch visits and heaps of emails and calls. Absolutely don't care. Am sending a summons for Small Claims Court for 13 months times R499 and the cancellation fee with interest.