6max 1/2

PREFLOP: Donk limps MP; Villain raises 16 CO; I flat SB ATo: Donk call.

FLOP: A77o; I check; Donk checks; Villain bet 1/2 pot; I c/c; Donk folds.

TURN: A779o; I check; Villain bet 3/4 pot --- ???

He knows that I don't have AK, AQ in my range. Am I suppose to just give up here? What's the point of calling the flop if he barrels turn so often? I hate spots where villain knows my range is capped and can exploit me.