Excessive data usage... getting billed $$$

Your modem readings are looking real good but has nothing to do with your data usage. You might have a neighbor that is in range of your wireless router that has been able to gain access it and is using your internet to do whatever. It might be something simple such as streaming moves from Netflix or related services which could easily use a lot of data bandwidth.

I would check the Cox Data Usage Meter on the Cox website. Not only will it show your monthly data usage it will show daily usage as well. I would try disconnecting your cable modem completely for one day if you can. Then check the Cox Data Usage Meter to see if there was any data usage for that day. There shouldn't be. Also know that Netflix that is on the Contour cable box uses internet data when you stream movies from Netflix.

Would be great if you figure out the issue and report back here on the forum what the issue was. It might help other users that are having the same high data usage as you..