Internet/mobile contract not honored

I signed up to get a discounted price on my internet for 12 months if I also signed up for xfinity mobile.  I have an email  that says my order is confirmed with my estimated monthly internet bill.   I lowered my internet speed to get this price.  For 3 months my bill has not reflected this price.  I have talked to more than one person until I finally got someone that said they can see that my contract says what I said it did.  They made notes and had me call billing the next day.  The billing person agreed read the notes, put me on hold and and got a ticket number from their supervisor saying they would fix it and send me an email.    This did not happen.  I have talked to 2 people since then.  They both said that promotion is not possible, I have a good price and I can not get the price that I have in my order confirmation.  I am paying $20 per month more than was agreed.    One person I talked to actually sent me another mobile phone that I am being charged for by saying they were sending me a free device to help me troubleshoot my issue (I did say I don't need that, just please fix my bill).  A week later I received a phone that I did not ask for that so now I have to go in and fedex it back to hopefully get the new charge off my mobile bill.  It is really frustrating to sign up and agree on a price to not have it honored.  

Tonight I talked to someone that looked at the account and just kept repeating no, your bill is not that price and then we got disconnected.  I'm not sure if they hung up on me or if the line dropped but they did not call me back.