Price increase of $60+ per month with no warning

Hello,

I received an email today reflecting a bill of over $144, which is more than $60 over what I have been paying. While on chat with a rep I was told my promo offer was expired and that was my new monthly cost. I asked the rep what promo I had as I do not remember having a promo and the rep couldn't answer the question. While chatting, I decided to check local competitors and noticed AT&T Fiber is much, much cheaper for both Gig speed and 5 Gig speed (Xfinity only offers 2 Gig speed in my area), both with no extra cost for unlimited data or monthly modem fees. I mentioned this to the rep who stated the best offer Xfinity has for me is just under $100 for Gig speed. If this is truly the case, I'm fine switching, but wanted to know if this is the best that can be offered.