Mobile Billing Issue

I need a corporate phone number to get a hold of whoever is over Xfinity mobile. I was owed $280 because I was charged for two lines when I had one. I was told at first that it would be refunded. They refunded me $90 and I have not seen the rest. I called back then I was told it was going to be credited to my account so I wouldn’t have to pay a phone bill. Now here we are today and my phone is disconnected. I called yesterday then I was told a third story. I was told that I received an email that gave me options of how to get my money and I needed to look for that. So I told them I felt like they should restore my phone because it was not my fault. The manager told me no they would not be turning my phone on or helping me with anything else. I looked for the email. There is no such email. I need a phone number for somebody that knows what they’re doing at Xfinity. I want my phone turned back on and I want my money back. If not, I will make sure I go on every review there is to let people know not to ever get a cell phone through Xfinity.