I'm not quite sure what you're referring to when you say, "I think it is a pretty poor system that cant see usage past 15 hrs in the past," but if you'd like help in determining either what's using the data, or where the problem lies, please start a new topic in the Tech Support section.
If you'd like help with your speed and data usage issues, please start a new topic in Tech Support.
Streaming is a very data intensive activity, especially if done in HD. Depending on the streaming source, the amount of data used can be anywhere from about 350MB per hour in LD, 700MB per hour in SD, and 3GB per hour in HD. With this said, if it's been no more than a few months since your sales call, you can request a sales call review to determine if the sales associate set proper expectations. If it's determined that they didn't you may have recourse. If you would like to request that sales call review, please start a new topic in the "myAccount and Billing" section.