How to?

Sometimes, funny things happen in life. What's with us having to do something for someone just because we HAD to? It's not that we owe the person or the like of that. We do it for them just because we are human. It's our instinct to help each other. Instead of saying thank you, people tell that we just had to do it for them.

???!!

And if we do not do them, they start making a fuss as if it's mandatory for us to do so.

How do we deal with them?