Should I let the money go and keep the friend?

I have been part of a trio of friends for 2 years. They are both great people but one of them has gotten into drugs and other risky behavior. I was going to loan a person $20 and I asked this friend, lets say jane, to give it to the other person for me. A day later the other person didnt need it so I asked for the money back, Jane refused and sent mean txt messages. She was really inappropriate and petty then all of a sudden she decided we were to be friends again. BUT she still wont give back the money