Rain - debited account after cancellation

I cancelled my rain one wifi a month in advance. The rain agent confirmed with me that I wouldn't be debited for this amount the next month. My account was still debited in error. I phoned rain. The agent confirmed i was billed in error and sent my request for a refund, that was two weeks ago. I phoned again last week and chatted to rain on Facebook and now they are saying that my router was post paid legacy plan when my billing history proves I have paid every single month before I even received network from this router and and an extra month now that i was billed. I am being sent pillar to post. And nobody has contacted me Like the rain agents promised. The service is very very poor. Many of my friends are leaving rain and I myself am thinking of cancelling my final plan with them. If they run their business by *****ing money. I don't want to deal with them