When you do good do Something for those who can never repay you with zero expectation and absolutely no returns, you will know and experience that good really do come to you in small and large ways. It’s Karma!
Some might abuse you or some might not thank you properly, but it is not about having something in return. Doing good, promotes good to others or so that is what I believe in. There is a quote like, “Treat everyone with politeness, even those who are rude to you – not because they are nice, but because you are.” and people who usually say what you say are the people who are not seen for the deeds they have done, but its okay, as long as you know what you are doing and what you think for yourself. ~ Jr Alcuizar Barredo
Don’t search your happiness in others. It will make you feel alone, but search it in yourself, you will feel happy even if you are alone.