False incentives

Hello, when I first signed up for internet I was told I would get a free year of mobile service included with my plan. It was even in my Xfinity app under the internet box is a mobile box and it said claim free year of mobile service!! I clicked on that to claim the free mobile service. It gave me a line and now is charging me!! I spoke to representatives in the chat and they said that promotion is only for a diff tier not the one I have. That wrong!! It was offered to me and I signed up through where it said for me to claim it!! That's false advertisement. I'm very upset. I have screenshots to prove it. It was offered to me and in my account!! It said I'm eligible!!