Do I have the right to be mad?

My boyfriend won't text me for hours straight and when I confront him he gets pissed off and says "I was busy at work" or "I was sleeping" or some bs. But I'll see him post on FB Or look at my snapchats etc. like is it really that hard to take 30seconds to send a text? I'm not getting mad over 30min. I'm talking like hours and sometimes 24hrs... Today I told him, " you can't text me back bc your so busy but you can get on social media" and he said " I don't wanna hear this bs I'm not in the mood" so I haven't heard from him since this morning.  Do I have a right to be mad?