Thank you for your inquiry. I would suggest contacting Prepay customer service at 888-294-6804 about the My Verizon application to see if it is compatible with prepaid. For checking your data usage, you can actually call #MIN and you would get information about your minutes and data. #DATA will route you to customer service and you can check data thru the automated system. See here for more information about checking data thru #MIN and #DATA.
I've tried all of that and NOTHING works to get your data usage if your a prepaid customer. I wish the Verizon reps would get better educated and STOP telling us that you can get the data usage..... I've been told that they are working on it, but I think its a load of crap.