I've been friends with someone for years but not anymore.
Why aren't you their friend anymore?
Because they're a swindler, a thief and a lowlife harasser.
Not all friendships are meant to last forever and there are times when it's best to end them and part ways. Toxic people and friendships are not healthy and recognizing this is a good thing for you.
I do feel much better since I cut contact with them.
It's great that you feel better now that your toxic friend is out of your life. There's no reason for you to keep associating with someone who isn't good for your mental health.