i got a reply from my insurance company they said:
Thank you for your recent email. We are aware that Virgin can be a little tricky to deal with in regards to the Proof of Usage and Proof of Blacklisting. For usage, a billing statement showing the activity for your phone number is sufficient. For the Proof of Blacklisting, please go to this web address https://keepup.virginmedia.com/lostandstolenphones, fill in the online form with the IMEI number of your handset and forward us the email confirmation you receive. In addition, we still require the following:
Proof of purchase for your handset: Please forward to this office any paperwork you may have been given when you purchased the handset showing the make, model, IMEI number and purchase date. Alternatively, please provide confirmation of these details from your service provider/retailer as they will be able to provide you with a duplicate invoice.
Further Incident details: We require your further and more specific details as to the exact circumstances surrounding the incident for which you are claiming. Can you provide a detailed timeline of events that led up to the incident for which you are claiming.