can't make calls on android 6.0.1

[Akastil]

hello!

I searched on many forums for the solution but i couldn't find any, thats the reason why I am writing it here. I hope somebody can help me fix this.

Few days ago i bought a Samsung Galaxy A5 (2016) model: SM-A510F, Android 6.0.1
I had 2 normal calls and then the problems started. When i want to call someone I don't hear anything and if somebody is calling me, the phone rings but when I want to answer the call: 1. as I swipe the green icon the call ends or 2. I answer the call, but can't hear anything, and the other person can't hear me.
Then I get a "missed call" message, so i guess it is not because of the network.
I checked the permissions settings, but I still have the problem.
But the funny thing is calls on apps like WhatsApp or FB Messenger work fine.
So it's not a problem with the microphone..

I hope someone knows the solution, will help me and the other people with the same problem

UPDATE[29.5.2017]: i was "playing" with the settings and somehow today i had 2 normal calls, everything worked fine and after that the problem came back.
P.S. I couldn't find the internet calls settings :S

 

[jasonandrews25788]

I think it's an issue with your carrier.

 

[A17]

This could be caused by a wifi calling app. Navigate to settings > call settings > (internet call) calling account settings > untick "receive incoming calls" and make sure it says "use internet calling only for internet calls".
Hope this helps