This is really hard man, in my opinion you can do 2 things :
1- hire a lawyer if you can afford it, and if not, i think there are many members here can help you financially to do that, helping a fellow human..

2- Knock his door , company or home, check if you know anyone who has contacts with police friends, then you can take him to court, telling them that you are trying to contact him , to settle your debt , but he is not answering you.

Hope your problem is solved asap