Different to the issue where wifi count is mixed up with cellular count, how many others are experiencing erroneous data on their bills in comparison to their native ios cell data counter? I've faced constant problems with an australian provider, Telstra. I believe problem here lies in the integrity of IP connection over cellular reception. Radio waves are susceptible to interference and congestion, particularly in busy areas during busy times. I have routinely observed a loss of an ip connection due to both congestion and reception. The design of network device infrastructure dictates that phones do not report their cell data usage according to the device data counters (hex / binary ticker that counts packets in and out of the device), such as ios' native cell data counter, found at Settings/ General /Usage.... Cellular companies monitor data served and received. Therefore in an instance where you have a congested network or fringe area and a loss of ip connection occurs, or if an app requests data by way of process, it may be served by your mobile data provider repeatedly, even if your phone only recieves it once and you have an uninterrupted user experience. Say, streamed video, 300 meg file you hit, you may have had 410-700 meg sent to your cellular ip address even though you only get 300 meg of practical data ACTUALLY recieved by the phone. Believe it or not you are billed on the 410-700meg theoretical transmission, not the practical data volume you recieved. If your ip connection is spotty, or you are in a congested area, or you network hop a lot, your'e probably susceptible to the same problem as I and countless others. Networks won't admit the issue because it's related to network infrastructure. The Wifi-Cellular cock up ios is a different issue and from what I've read, related to priority instructions for push ip connection. The above strictly refers to cell data, and erroneous cellular only reporting.