When taken advantage of, 

view it as a karmic repayment 

or as something put away for the future.

When someone takes advantage of us, one of two things have transpired: either we owe the person a karmic debt or we don’t. Owing the person, being taken advantage of means we have reduced or perhaps even canceled it. Having spent lifetimes creating such debts, eliminating just one seems a mere drop in the bucket. But if we can gladly repay it, we’ll do more than just settle a karmic score. Because our grasp of karma is deepening, we’ll have progressed in our cultivation. So our repayment is a good thing! Not owing someone, being taken advantage of means that since we don’t owe him, he will have incurred a future debt to us. Having a karmic credit is also a good thing. But let’s progress here too. Not wanting to incur another enmity, we will forgive the person of his future debt to us. So either way, when properly viewed, being taken advantage of is a karmic benefit.