I can not receive phone calls or make phone calls

So many things can affect your service.

1) Blacklist: Your device, if received used, or if it had been reported lost, could easily be under the global blacklist, which will need to be removed from the list by the original purchaser of the device.

2) SIM card issues: Your SIM may not be functioning properly, OR your device may be locked to a different provider than the SIM you have installed.

3) Software Malfunction: Your software could have become corrupt, in which case a factory reset will fix your issue. (Be sure to know this process will erase all of your data)

4) Antenna strength: Your CoAxial Antennas may be malfunctioning. replacing these may fix your issue.

5) Board Level Pickup failure: Your pickups may be failing on your board, in which case a quick Isolated Solder Reflow of the local areas may fix your issue

6) Broadband IC Failure. Your boards IC could be failing. Replacing the Chipset could fix your issue.

7) Integrated board level failure: there is a possibility that the board itself is failing. you may need a logic board replacement to get any further with the device.