Runako

Exactly. Getting a police incident no. should have been done asap.

See if you can do it now and provide the details. Then submit the claim to the insurers or initiate with your own company and let the insurers sort it out.

Your insurer just doesn't want the hassle of administering the claim, possibly because the event happened so long ago and the circumstances make it fit for dispute. But between the two companies, they can sort this out a lot quicker than you can (as is evident so far).