hopeless service provider

The worse customer service from this institution. paid and received the device on the 02/09/2021 and it worked. 3 days later the service just stops. 05/09/2021 logged the 1st call to sort the problem on the day, everyday for 20days with each call lasting over an hour every time to have this problem sorted. still no internet 25 days later, and the only response their technicians give, reset and reboot system. reset and reboot router. call after call after call. logged a ticket to have this problem sorted...same responses, reset and reboot. no supervisor to handle the query, no manager to respond with any feedback. is this the service that MTN wishes to relay to customers? is my only option to have this sorted writing to ISPA for assistance?