Now I may be wrong and this may also be a leak in my game, but why wouldn't you call the 3bet?

.82 call (total preflop) into a 6.76 stack is 8.24:1. Someone 3betting here (unless it's light i suppose) is pretty much saying "hey if you hit your set, I'ma give you my stack". It is read dependent though. I would be more likely to play this against a relatively tight player as their chance for staying committed to their hand is higher than a Laggy individual.

By no means what I just said is "DA TRUTH", cause I'm concerned this may be a leak in my game too.