Sometimes when your iPhone experiences issues related to your cellular network (no or poor service, calls going straight to voicemail), the problem is stemming from the cellular network, not the iPhone itself.
Below are the support numbers of major wireless carriers to contact if you're experiencing problems.
How Do I Contact My Wireless Carrier?
How To Contact Your Wireless Carrier
- Verizon: 1-(800)-922-0204
- Sprint: 1-(888)-211-4727
- AT&T: 1-(800)-331-0500
- T-Mobile: 1-(877)-746-0909