I am having the same issues. For the past couple of months somehow I have managed to use over half of my 1.2TB in a matter of 10 days when my home has NEVER done this before. I've worked with Comcast people for hours with no resolve and being told it's on my end. I got a tracker for my phone and it has not even managed to use 7 GB in 10 days as an example. Last year I use to play a lot of video games and so has my roomate and we still never went over then. The last few months we have just been working with hardly any gaming at all and streaming but not nearly using our internet at all like we use to. I have listened to every "Trick" that comcast techs and reps have suggested for the past few months (When I never have had to before) and it seems to be getting worse somehow. These are the same devices I've had for years now and still no answer and just being told it's on my end. Their own app that they tell me to use that just shows percentages is even showing that my devices don't appear to be using much at all. Many people are reporting this inflation starting in September so we are not alone. With no answer I've had to resort to going to the FCC over this matter. Many people have placed Network Trackers on their gateways and are showing the inflation when they are in fact not using the recorded usage they are being quoted for by Comcast. I encourage Comcast to research their own Community forms as this is becoming a big issue and many are noticing.
@Caius2016 I am sorry to hear about your troubles and the experience you have had. This is certainly not what we want for our loyal Comcast customers. I would be happy to help. Can you send me a private message with your full name and service address? You can send a private message by clicking my username and selecting send message. I look forward to hearing from you.