Hahahaha, isn't it funny how when they won't stop harrasing us, we get mad...and then when they hang up on us, we still get mad? It's never nice to hang up on someone while they're in the middle of a sentence, if they were the one to call you in the first place. I don't even utter a sound when a telemarketer calls, I hang up right away, I can't stand them. Hang up right away next time so you always beat them to the punch! :)
If his manager found out, Im sure he'd get fired. They are not allowed to hang up. Maybe he was just having a bad day and was tired of all the hang-ups he gets. Some people are pretty rude to telemarketers, so maybe you should cut him some slack.