I get angry and frustrated when I get 'silence' as an answer.
I think it's because of past events, when I'd seek out so called "friends" for comfort and security in times of trouble, I'd be ignored or brushed off with a one-liner, even after repeating myself.
Therefore when someone doesn't respond I start getting angry and feeling resentment and people these days probably wouldn't even know it until it comes up bites them in the ass. This reaction of mine is practically instinctive, it will happen because it's the only way of responding to the scenario I know. I've told myself to try and "chill" before but I still get angry regardless.