What should I do now.?

you are not at all at fault, so dont worry about it.. you just needed a headset that functions, and you didnt get it even after u asked for it three times.. + he yelled at you.. in this situation, he might have misunderstood what u were asking for, or thought that u didnt undrstand what he told u? i wouldnt have thought that he's just pissed off.. just chill... i think it was his bad day and u unfortunately became his victim of venting it out..