I have an unlocked ATT phone on tmobile and live in a mostly refarmed area. I've been connected to the network three times over the past couple weeks and get a solid signal with very strong 3G+ speeds. My problem is that whenever I leave the refarmed area, the phone reverts back to edge, which is all fine. But the phone is unable to pick up the refarmed signal once I go back to the refarmed area. I've tried toggling it on/off and messing with the plane mode, but it always goes back to edge. Is there any way to force the phone to search for the stronger signal?