Travel Insurance Claim - Old receipts for all the stuff lost

I am a frequelent traveller. In the August this year, at London Heathrow airport, my hand luggage was stolen by a thief. I am insured with New India Assurance, which wanted receipts to confirm the validity of my claim. I did not have receipts as all the stuff lost was easily over a year old and some of the stuff was more than a year old. Please guide how to solve the above issue.

I think that is fair enough. You can check your credit card/bank statements for the past purchases. And try to get the duplicate receipt if possible.
Have you got photos of the goods, you have lost? They might be helpful for the insurance company.