I don't quite understand your question. If you are on WiFi, your phone would use that rather than your wireless data plan.

 

That's what it's supposed to do. Every android phone does that. You don't have to turn on data to send or receive a pic.

 

I'm having the same issue. Since the new update, phone doesn't automatically switch between WIFI and Mobile Data. If you have Mobile Data selected as on, it overides WIFI. Have you manually keep turning on and off. And if on WIFI, it won't send or receive PICS. You have to manually turn on Mobile Data then it will download. Very irritating. Old version you could have both on and if a WIFI was found, it locked onto wifi until you were out of range then automatically connected to Mobile. Also, terrible battery drain still

 

not having that issue here in the states with the update. virgin mobile.

maybe try enabling or disabling the connection helper. I have mine
disabled as I don't want or need the wifi draining my battery
all the time at work.

 

There is a selection in advanced wi-fi settings to "Auto Network Switch". how is yours set?

 

Thanks. Yes I saw that setting, Auto Network Switch...it is checked as on. There is also a tag titled, "Auto Connect - Automatically connect to ATT&T Wifi hotspot when detected"....this one I do not have checked on....

 

Perhaps you should turn that setting off.