Okay well i just upgraded to the the DHD and my data usage is 750mb a month, i have just revived the phone about 3 days ago and have been using wifi most of the time to internet browse while at home, i have never used the internet apart from maybe weather when auto update. But i recived a text saying thati was close to going over my 750mb data usage? have i been using the mobile internet even when my wifi was on?