Extra charges on my billing plan

I noticed on my 11/25 my bill shows past due $46.51 and new charges $180 I don't understand how my monthly bill went from $110 to $180 something is definitely incorrect I have no made any changes to my bill and definitely displeased with Xfinity services not one agent could give me a good explanation and they tried to manipulate the question being asked I will definitely be shopping around asap