Help intermittent wifi/ mobile internet connection problems


Hi there recently got the s3 and very hapoy but for one annoying bug. At random the wifi or mobile internet ( doesnt matter which) will seem to stop working - pages dont load, facebook and email wo nt refresh. Generally if one not working (say wifi) the other will be ok if you switch to it ( say mobile data in this case, could be other way round too). No problems on surface - there is signal, and radar light's at top are on. Will work fine sometime later. My girlfriend had the same problen with same phone, but not at same time ( ill be fine while she is off, then both fine, then me off.) We are in uk on orange/ tmobile if that helps. Hope someone else has this and knows a fix?