Since you have stated that you have tried everything then the only thing left to do is to contact your carrier and inquire about incoming calls. Do any of the incoming calls get to voicemail? I am going to list the things to double check below and you may have checked them all however in case you missed something then here they are:
- Check to see that the Silent switch is not set to ON. Silent switch is located on the Top Left Side of your iPhone.
- Open Settings ➔ Sounds & Haptics ➔ Ringer and Alerts : Make sure this is not set to OFF or too Low. Set Change with Buttons to OFF. Below that Make sure that there is a Ringtone selected.
- Check to see that Do Not Disturb is set to OFF. Open Settings ➔ Do Not Disturb : Set this to OFF
- Check to see that Silence Unknown Callers is set to OFF. Open Settings ➔ Phone ➔ Silence Unknown Callers : Set this to OFF
- Make sure that a ringer sound is assigned. Open Settings ➔ Sounds & Haptics ➔ Ringtone : Ensure that a Ringtone is assigned here.
Axel F.