3G Internet won't turn on / iPhone?

Please why? I have settings turn EDGE ON - 3G ON - data roaming OFF ( i tried on too but nothing )
It turns on but after sometime but right now i'm on EDGE only. Why? So slow.

YOu should reset it settings or restore factory settings after disconnecting it and reconnect it.

You should reset it settings or restore factory settings after disconnecting it and reconnect it.

You are not in an area with good reception. It is the carrier.