Okay we have either have a lot of people who have chosen not to read the thread or we have a lot of dense folk on OcUK.
I'll put this in big letters so everyone can read it.
The OP ordered goods and they were sent to his old address.
Either because he provided the incorrect address, or the company he purchased from still had his old address on file.
The people who received it don't want to give it back so the company has given the OP a replacement.
The only people who are out of pocket are the company who sent the goods, and it is up to them how they pursue it.
The delivery courier has done NOTHING wrong.
The OP should not be pursuing this matter, it is not up to him to play vigilante.
It's not going to go to court because it's got bog all to do with the OP!
His issue is resolved.
You sound like the kind of person that would walk by someone stealing something in the supermarket because "it's not my problem". Fair enough that's a choice you make. But where do you draw the line? These people have stolen goods. Why can't the OP report them? That's his choice.