xfinity internet and Mobile

I have switched from T mobile and xfinity. When I made the switch , one of the agents gave me an offer that the line was free of cost for 1 year. At the same time, I have moved to a new address. The agent activated the line on my old account and Bundle PROMO was applied to the new account. I spent like 12 hrs talking to the agent to resolve this issue. Now, I see that my mobile bill is $43, including taxes. I even went to the local xfinity store and they suggested me to go to the corporate office. I drove 20 miles to the corporate office and they filed the escalation ticket, and it is still not resolved. I am very disappointed with the customer service and the local store. This was a simple billing issue, and they were unable to resolve it. They wasted my time. They were forcing me to buy a 2nd line so that 1 line will be free and for the first line I have to pay $43.