How you unblock a number from call rejection mode

[AC Question]

I own Moto G 1st Gen with Android Lolli-Pop.

I have been facing a strange issue. Some how (i don't know how it happened) one of the number from my contact is getting blocked.

Whenever i get a call from that number , the call is rejected and quick response sms is sent to the caller.

 

[B. Diddy]

Welcome to Android Central! Open your Contacts app, tap the contact that's getting blocked, tap Menu, and make sure "All Calls to Voicemail" is unchecked.

If that doesn't work, open the Phone app, tap Menu>Settings, and look in the Call Settings for any call blocking options.