Pathetic service and billing department

I cancelled my LTE with Supersonic 1.5 years ago. I was not made aware that the router would have to be returned after cancellation. Fast forward to 1.5 years later, I received an SMS after hours informing me that my account will be debited for R2499 and it was debited 4 hours later without any proper communication or reason. When I called the call centre, they mentioned it was for the router. They scheduled for the courier company to collect it 2 months ago and promised to refund my money in 21 days. 2 months later and they still haven't returned my money. I've called them countless times, they dont answer their phone lines, they take forever to respond via WhatsApp, billing never seems to help. I've requested over 10 call backs and never received a call back once. Ive spent so much airtime calling them, only for them to never answer / cut my calls. Their service is actually pathetic and I'm not even a customer. Never ever buy products with Supersonic, they have caused me so much inconvenience and made my life hell! You will regret it in the long run.