Xfinity scammed me

I wanted home WiFi for my new apartment. When I called XFINITY, the lady who set up my account told me that if I also take the mobile connection -unlimited plan, she can bring my total bill to 50 (after asking how much I paid for my then MINT mobile connection). So I transferred to XFINITY even when I had already paid for 2 months in advance to Mint as they said it was a combo offer and I have to activate Xfinity mobile. So first Month (March to April), I was charged around 100 including the setting up fee. The agents on chat on the Xfinity app said I will be only charged 50 from the next month April to May. But again this time I am charged around 75! When I called at 18889364968 and explained, the guy told me I can change my plan to by the gigs and can get a promotional offer of 3 gigs for 25. Lies again!! Because  after holding for another 40 min the lady told me there is no such offer!!! Are you all scammers?!!