Hello Yuekutea99
This incident is regrettable and I understand your frustration, but how could we help you in this community?
Railways are not responsible for your luggage. You could send a complaint with a registered letter if necessary, for example to obtain a refund from your travel insurance. You have 3 months to do it. Otherwise I don’t think that it is useful, the police certainly doesn’t invertigate for every solen luggage.
Kind regards
Danhiel