How to read online prepaid bill for data useage? Rogue data noted.

[marwr]

I moved all of our phones from Postpaid to Prepaid in June.  My husband went to Straight Talk - he does not use data.  I bought a Moto G and have had no problem with data use.  My daughter is using her iphone 4s (updated to 7.1.2 ios) and has had rogue data use almost daily.  On prepaid most months she was below 1 GB - she uses wifi most of the time and never downloads, watches videos or listens to music on cellular.  On her bill, almost daily there is a 1300-1500 data use in the evening - it shows up under the "minutes" column in the adjustments of the online bill.  This can NOT be minutes - is it kbs?  Asked at the Verizon store and they didn't know.  Last month (her first ) she went over her data and we can't figure out what is doing it.  She's turned off all apps using cellular but it seems that the iphone seems to have a preference for wi-fi instead of cellular.  Any suggestions?  And is it KBs or minutes or what on her bill?  Any help would be appreciated.

[gabrielaid]

Hello marwr ,  in the Vzw account you just going to see the minutes. If you want to know how many MB do you have. I can dial #3282 on the phone or use myveerizon app: it shows the usage in MB. When you are using the wifi, you can disable the mobile networks to avoid the usage of data. well this is my recomendation   for further assistant call 888-294-6804 (customer service)