Police can't be taken serious, just seldom I met one who did his job in a professional way. Damn few, even if it's just directing the traffic.
The whole story sucks, kudos to you that you tried to solve it the correct way till the end.
Bottom line is you have the bike back, and that is a good achievement. Even though it was you at the end who had the damage and as well had to pay. I hate it that so many times other people screw up here, but do not suffer the consequences.
Anyway, shrug it off, lesson learned.