Hi guys im having a problem with my sons iphone 3gs, We live in Wanganui. He has a 2degrees sim card in it and he is with 2degrees as well. Every now and then the carrier will automatically change from 2 degrees and then go to voda nz, He can still make phone calls and texts and also receive them but the internet dont work. This is a problem because then i cannot use the find my iphone app to find where it is if it was to get lost or stolen. The only way to change it back is to do it manually by choosing the carrier.

If have left it manually so that it would hopefully stay on the 2degrees network but even like this it still automatically changes.

Why is it doing this? is it setup wrong?