Question

what we have to do when a person stop talking to you without any reason ?

Answer 1

Nothing, instead of getting hyper childish and throwing hissy fists, just walk your way out of even thinking about that person.
Yeah, you have all the rights to assume that the person being talked here of has gone total crazy and he's better off getting along with his folks from the asylum.

Answer 2

Hello friend

if somebody stop talking to you without no reason- you have asked them "what happen? Did i do something wrong?"
But you have to asked them with patients instead of angry face etc.
After all if they love you than they will reply you for sure.

This is my advice.....hope it hepls.