Credit not sent to me

I left Xfinity over a year ago. I left with a credit of $1123.76 due to over billing by Xfinity because you lost my mobile phone trade ins for months. I've been told several times that I would get refund and have received emails saying it would be credited to my account. 

I have received no credit. I called billing one last time and they claim they cannot see it despite the rep in the store seeing it on my account just a few days ago. Are you going to send me my money or do I need to report this to the FCC and MN States Attorney?