Call failed

I'm disappointed from ios 8

am using iPhone 6 plus when I trying to calling it show call failed I was used 8.1.1 I upgraded to 8.1.2 and still I have same issue. However, again I upgra it to latest ios 8.1.3 and the issue not solved alwayes show call failed.

Moreover, when I want to call I go to setting ▶️ Phone ▶️ Show my caller ID, later I can make calling after that the issue again show to me !!

please how can I solve that. We are looking for explaining from Apple because I make research online I found so many people have same issue.

Best regards,

Hameed Marhoon