Bad service & poor router quality

My line was activated on 01/10/2025 and the router worked well until 25/10/2025 at which it just could switch on, even after changing the power supply cable. I’ve called supersonic or MTN Fibre at least twice every week with no resolution. On Friday 07/10/2025 I was told that the accounts department just has quote me collection fees and they will come get the router, investigate the source of the breakdown and if it’s mechanical then they will give me a new one because of warranty. I have never heard anything from them since and every time I call - they keep stating that they will escalate. I’ve had such bad experience that I am simply going to cancel this contract. 3 weeks without a router, if I didn’t have my router from my previous ISP, it would have been 3 weeks without internet. Horrible customer experience and will never recommend MTN fibre or supersonic