Poor service

I have been using rain for over a year on unlimited 4g network. Though i had issues here and there with poor network i decided to stay with because it was the cheapest option that was available. My real problem started when i upgraded to 5g on black friday. The router was delivered to me and i tried to set it up but there was no network connection at all. After numerous attempts to get rain to solve the problem they sent me an outdoor router and still no network. I have since been asking for a refund from rain but to no avail. I cancelled both my sim cards end November for Dec. But up to now rain is still debiting my account. I have phoned, email but they keep on promising to get back to me but nothing. Rain is a big ******* i dont know what to do to stop this.