Even after resetting my iPhone is not receiving or making calls

FIRST: Are there missed calls in Phone/Recents on the phone? If they are not the problem is in the network, because the calls aren’t getting to your phone. Contact your carrier: 

• check with your carrier that they don’t have a local outage, and that you didn’t have any settings that would have immediately invoked voicemail, such as call forwarding.
• check up on them at Down Detector - Crowdsourced outage checker

If they are in Recents here’s what to check:

• Check the MUTE switch on the left side of the phone, above the volume buttons. It should be towards the screen
• Check the volume setting. With the Home screen displayed, press the VOLUME UP button on the left side of the phone. It’s above the VOLUME DOWN button.
• Go to Settings/Phone. There’s a switch for Silence Unknown Callers. If it is on any calls from numbers not in your contacts will go directly to voicemail.
• Also in Settings/Phone: Make sure Call Forwarding is off.
• iOS 14 & older: Go to Settings/Do not Disturb. Turn it off if it is on. Also turn off Scheduled. With both off none of the other switches there matter.
• iOS 15: Go to Settings/Focus, and verify that all focus settings are disabled.
• iOS 16: Open the Control Center and turn off Focus.
• Go to Settings/Sounds & Haptics. Make sure there is a sound assigned to Ringtone.
• Go to Settings/Accessibility/Touch/Call Audio Routing and make sure Auto-Answer Calls is off.
• Go to Settings/Screen Time/Communications Limits. Tap each of the 2 entries and make sure both are “Everyone"
• Restart your phone-->Restart your iPhone, iPad, or iPod touch - Apple Support
• If all else fails, talk your carrier into replacing your SIM card (thanks to ASC user DShelbyD)

(written by Lawrence Finch)

If you receive text and data but cannot make or receive calls there is something misconfigured in your account. Contact your carrier. They will probably replace the SIM, which may fix it, but I suspect your account is not provisioned correctly in their system.

ChamaleeS wrote:

Yes, the outgoing calls are in the Recents.

But when I try to make a call, it gets 'CALL FAILED'.

I still think this is a carrier issue. First-tier customer service reps at sell phone companies have quotas to meet and they need to get the customer off the line as soon as possible. They are also not tech support so, their ability to diagnose issues is limited. I would call and see if you can escalate the issue to actual tech support at your carrier. That can be rather challenging as they want to do everything they can to avoid that and...get you off the phone.

You might also try backing up the phone. Then, restoring it as new. Don't yet restore the back up. Test if first. If it works fine, try restoring the back up. If that causes the problem to recur, there may be something in your data that's causing the issue.

I recommend restoring using a computer as that will install a fresh version of iOS.

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

Try turning off silent mode or turning up the notification sounds. That’s all I know

ChamaleeS wrote:

Since you brought up the carrier issue, I tried inserting another SIM card from a different carrier(this time Dialog). Now the iPhone did not recognize the new sim card, it said NO SERVICE. So I removed the new sim card and reinserted my old sim card from Mobitel. The old sim displays signal and i receive text messages and data as usual. But no incoming or outgoing calls.

Sounds as if the phone may be locked to your current carrier.

Now I'm even more confused. Do you think it could be an issue with the sim tray?

No.

ChamaleeS wrote:

Hello Idris, thank you for your reply. Recents are on my call list (calls i have been trying to make but "CALL FAILED", but not any incoming calls- i get only a CALL ALERT)

I'm not quite clear what you mean by that. Are the calls in Recents or not?

Well, I have reset my phone once more hoping i could have access to the Call Forwarding, but still getting the spinning wheel.

So are you saying that you can see the Call Forwarding setting but can't change it?

Have you contacted your carrier? If not, I'd suggest doing that.