I just bought a new unlock gsm phone. xgody x500. I bought a new ptel sim card. I activated the sim. The phone keeps saying no sim card installed and won't let me use my service. But i was sitting in my car at a gas station and i my service started to work. Then it went back to the sim card not installed. I tried installing all kinds of apn apps. None worked. Kept saying not allowed 3rd party apps to write apn settings. i tried rooting my phone that did'nt work. Can anyone please help me.