Be "assured" you will not get your refund

I have gone through talking with xfinity agents FIVE times. A bill was erroneously posted to my account after canceling service at one location and starting at another. I spoke with an agent who "assured" me I had nothing due and nothing would be drawn out of my account. Go figure, the $50 was auto billed/withdrawn out of my account. I spoke to two online agents over the following months who assured me my refund was on the way. By the third, agent, they informed me that a check had already been sent... Of course, it had been sent to my old address where I no longer lived (hence why I canceled my service for that location). After explaining this to the agent I was again assured the money would be refunded to my bank account to avoid any issues with mailing to the wrong address again. This never happened.  I again contacted an agent and requested to speak with someone on the phone who said she saw no record of me ever being issued a refund. After explaining my situation for the FIFTH time, she spoke with the finance department and assured me that I would get my refund with 3-5 business days to the account that it was drawn out of. It has now been three weeks and I have again received nothing. After 5 agents and 6+ months of waiting, I still have not received my refund and there is no way to contact the same xfinity agent so every single time I have to explain this whole story AGAIN and AGAIN and AGAIN.