“Promotion” scam

When I first signed up for Xfinity I was on a $35 a month plan when suddenly it went up to $55. They told me the “promotion” I signed up for ended. I didn’t realize I was in a promotion but since I was a new customer I figured maybe it was a new customer promotion I didn’t realize. Today I get another notice that my bill went up to $98. I contacted them and they tell me again that the promotion I was in ended. But I didn’t sign up for a “promotion” they simply took me off the one I was on so I thought I would just be paying the $55 for the rest of the time. The representative says on the 3rd page of the bill it says that I was on a promotion, who is looking and reading through the whole bill besides the number and the due date? And then the representative says they can sign me up for another promotion. Well if they signed me up without consent on the last one why didn’t they just sign me up for another. The system is very sketchy and the fact that they let my bill nearly double without any notice or tell me OR EVEN HAVE ME SIGN YES to a promotional plan seems almost illegal. They won’t offer money off the current plan and can’t seem to tell me how I was put on the other plan in the first place. Because if I knew I was going to be on a plan that expired I would have put a notice in my phone to contact them a month before that plan expired. VERY VERY POOR ON THEIR END.