Generosity of the heart

Someone told me today that I was being taken advantage of by some people close to me. Initially I wanted to disagree because the thought of me thinking badly of these people close to me just didn't sit very well, something like a bad thought and that I shouldn't be feeling that way. But the more I thought about it, the more I couldn't deny that that was indeed what was happening. I was being taken advantage of. Yet the reason why I felt like it was a bad thought to have, was that these are the very same people who have helped me in some other way. I know it's not you take advantage of me this way and I take advantage of you some other way kinda thing, yet it made me feel like I was being ungrateful for thinking of them this way because I had been at the receiving end of their help as well. 

I once read this quote during a temple tour - 人生最大的修养是宽容, that a person's greatest cultivation is tolerance. I think it actually takes a lot to not hold it against someone even when they do not treat you nicely. I for one cannot say that I am always able to do that. Maybe it would be easier to just not be so affected in the first place as everyone has different values.