Rain Refund due to me

Good morning

I signed up with Rain on their 5G router which was delivered in January but didn't connect. I emailed and they checked connection and said I don't have any therefore they will send the courier to come collect their device and refund me. To date I'm still not refunded whenever I email I receive response that they working on it. Last week they said we have processed it should be in your bank account. Told them it's not in, they requested a bank statement which I sent. Two days after sending a bank statement I emailed and they said the matter is with their manager, since then until now they do don't respond to my emails at all. I'm so disappointed in them thinking that I used them years back and the service was excellent. Now they gave me a very poor service and will never ever use them in my life.