Should i be mad with him?help please!!!!?

so this week this guy i've been seeing unofficially has been asking to hang out (he's asked 4-5 times) but i was actually busy every day he asked.. and he didn't really give me any fore-warning so by the time he asked i already had plans. he asked me again yesterday and i already told my friend i would hang out with her. well then he got mad and didn't text me back. when i called he didn't answer and he never called back. so today i tried to talk to him a little bit and told him i was free this weekend but he never texted back.. should i be mad that he's mad over something so dumb? what should i do???? please help!!!