I've tried for months to get a Flex device removed from my account...

I don't know how or where else to turn to for help at Xfinity except filing a complaint with the FCC after my many sincere attempts of getting this Flex device that's not in my possession (nor has it ever been) removed from my account. The representative who helped with my renewal lied to me when I explained that I didn't want Xfinity to send me any additional equipment as I own everything I need. They assured me I wouldn't be sent a Flex device. The next day following that conversation I got an email  stating they shipped a Flex to my address. That upset me enough that I cancelled that entire plan the representative sold me immediately. I rejected the package from the UPS driver, per Xfinity's instruction, and it made it back to wherever it came from. After multiple phone calls and chat support sessions over the course of two months, this Flex device is still registered to my account. Every person I've spoken to at Xfinity has told me different things and have even sworn up and down that they've corrected my account. Guess what, it's still not corrected and my account still reflects that this device is registered to me. This whole experience has been absolute insanity and frankly, I don't know what else I can do on my end. Any suggestions?