This is also when people say I am "too good" with some people who "Only take advantage" of others and they do not deserve kind treatment
This is something you should pay attention to and work on, it is a weakness and it can be dangerous for you. Even if you are a kind person you should have boundaries and this one is a healthy boundary to have.
If you know or are reasonably certain the other person is trying to draw kindness out of you then you really shouldn't reward that. Bad behavior shouldn't be rewarded.
The kindest I will be to such people is to just calmly turn them down, only ever escalating in aggression if they keep pushing beyond the simple no.
Here I will illustrate how I'd handle two similar scenarios.
Let's say I'm in a bar, waiting to order a drink. A hot chick rolls up and asks if I'd buy her a drink. I would say no, she has given me nothing and is immediately trying to get something from me. Doesn't matter if she puts on her charm or tries to flirt a little, I know why she does it and it's not because she likes me, she likes free drinks.
Let's say I'm in a bar, I spot a hot chick at the bar. I approach her, greet her and have at least a short conversation to determine if she's still appealing and then I might buy her a drink if I feel like it. Sure, she hasn't given me anything, but she hasn't tried taking anything either. I will never demand a drink or anything in return, but I will pay attention to whether she does give me anything in return without me ever asking. If she does it's a very good sign.
Also, if I'm at a bar and a hot chick buys me a drink you can be damn sure I will buy her a drink later. I fvcking hate being given something without giving something back. If there's an attitude in women I find extremely attractive it's that attitude. So if I'm buying a girl a drink it's really a sh!t test to see whether she has that attitude.
A nice guy buys her a drink in the hopes of buying her affection, he does it because he wants something from her. So when she keeps asking for another drink and he keeps buying, he's really emphasizing that he wants something from her AND that he's weak because he has not yet received anything in return for it.
Big difference.