There's not enough information here....
Is this a spouse with whom you have a long time invested?
Is it someone who rejected you because of some specific reason, or just because they didn't "love" you?
I've been in lots of situations like this, and I have to say...if someone doesn't want me, it's better to work at letting go...and without further contact with them. Why? Because it's like trying to milk blood from a stone if they truly don't want you.
So...if possible...tell us more about the situation.
Patty