Refund from Rain

Ive been calling rain for 2 and a half months for ky refund as they charged me just over R900 for my wifi.. . I sent back their old router they ssid once i do that ill get my refund still nothing up to this point. They said if I upgrade to latest router i will have better signal signal is the same very bad i cant even which TV or videos on my phone especially at night imagine paying so much for something you can barley use. Its frustrating every time i call they say refunds will call me but they do never. Ive been their clients for years and haven't skipped a payment not once their customer service is very poor