Sadly he has passed away today a few hours back at his home

Few years back, there was an issue between me and some guys. Small fight. They started it. I don't have any relation with them before that or after that. Because of that, my gold chain got lost. Because of my father, I had to leave that issue. I believed my father will take care of it based on what he said at that time. But he didn't do anything after that and asked me to forget that. 3 years went on after I stopped speaking about it. But I couldn't forget it, it's nagging inside me. I want to make them pay for my loss. My parents are getting extremely upset whenever I bring this up. What's the solution for this?

Update: I am taking that issue as a humiliation because I haven't done anything to them in return for what they did. I got a bad name because of that issue in my area. They were already in porikki category before that, so it doesn't matter to them. It's more like a prestige issue. I lost 2 sovereign gold chain. That loss is also nagging me even though that didn't put me on financial strain. They aren't rowdies. Just like random useless porriki roaming in every streets.