You asked for their help.
They refused.

Maybe they didn’t want to help.
Perhaps they were not in a position to help.

Couple of days later, they need your help. 

If you can help them, should you?
Or should you make this the best time to seek revenge?

Asking for help is good.
Not taking it personally when we don’t receive the help is better.
Not being personal, when the same person asks for help, is great!

Maturity in life is when someone rejects us and we don’t take it personally.
Bigger maturity is when they come back for our help and we help them.
Just because we can.