IPhone keeps saying searching?

For the last 2 days my iPhone 5s has been saying 'searching' where I should be connected to my provider. I can't receive calls/texts or send calls/texts and I can't turn my data on. I have tried a hard reset a few times, I've taken the SIM card out and reinserted if, and I have also reset the network settings a few times, does anyone know how to fix this?

Check your internet connection

You bill has been paid I assume? The phone was not dropped or has gotten wet?
Was there a recent OS update?