Abnormally reported high data usage

I have seen others complain about the same issue. I've had Xfinity now since July 2024. I have not added any devices aside from a smart door lock (no camera). I switched streaming services to Netflix but my streaming experience or usage has not changed. Only switched providers. No newly connected devices otherwise and I am using a Xfinity provider router. I went to the store because I was notified about an overage charge in the amount of $20 for going over my data limit (like we are in the 1990s). They said they will waive it this time but cannot give me any explanation for my data increasing DOUBLE for no reason at all. What they did offer me was to pay more by $10 each month for their unlimited plan. This sounds to me like a gimmick and shady business practices. Here is a breakdown of my data usage since signing up:

Jul - 190GB
Aug - 777GB
Sept - 416GB
Oct - 1.29TB !!!

I have been using the internet my whole life and never had to spend my whole Sunday waiting at the store or going onto message forums to complain about internet data caps or unexplained high internet usage before ever. This is quite ridiculous.