I've had this happen a few times in correspondence games. One time I was against a guy who was up a bishop for 3 pawns, had to give up the bishop for a pawn, and spent all of his time on each move, repeatedly asking for draws, before he finally gave up.
It happens. Just remember, the people doing it are the people who are stupid, not you.
I have been playing allot of live chess games lately. What annoys me is that when I am winning, people seem to spamming the draw button more and more often. I think its absolutely stupid and annoying. Then if I dont accept it, they start talking trash to me and start wasting my time.