Unusually High Internet usage !!

We seem to be having the same issue many others had in November 2020. We are currently over on our data usage. We have never been anywhere near getting to the 1.2 TB limit ever. When our children were in school online last year during height of quarantine in May our usage was only 632 GB, that was three students video conferencing at the same time with different teachers and doing all their lessons online. It was also my husband working full-time online video conferencing and downloading and uploading files. We don’t go over this limit ever. Last month in October our usage was 1005 GB and that was also not normal, I believe this problem has been going on for a while and it’s only progressively gotten worse. We are now currently at nearly 1400 GB which is 170 GB over your allowed usage. They charge you $10 for every 50 GB over limit. They only give you one leeway month in 12 months. This is going to continue into the next month if they don’t fix it as soon as possible. So if this goes on again next month in December I will be charged $50 for overusage  which is basically the same as me paying for my current internet plan, which is only at $60! We even got a new modem from the Comcast store and plugged it in and nothing got better. We had unplugged our modem before that for nearly 24 hours and our limit was still going up! How were we using data when we weren’t even hooked up to it? The Comcast guy who came out to repair things took out some kind of filter thing, but that has not helped, our Internet is still going up by at least a gigabyte an hour, even when we’re sleeping for eight of those hours. With the Comcast modem I’m able to pause devices and I have paused anything that we’re not currently using or need access to. Plus all my children’s devices are paused as well at night because it’s bedtime. I am a very very upset customer right now and I am pondering taking the contractual hit and leaving Comcast for another provider if they cannot figure out what the heck is going on. Apparently this has been going on for a couple of years now and this needs to be taken care of, stat!! Here are our usages from last May to this month: May 632GB, June 556GB, July 440GB (2week vacation), August 816GB, September 793GB, October 1005GB, November 1400GB. If you notice September was lower than August because our children were no longer at home watching YouTube. They were at school. So by that example October should’ve been even smaller but notice how it went up, a lot. We don’t even stream at night anymore we only watch our DVDs and our Blu-ray‘s!! Fix this problem now!