Wow! What a tough spot to be in. First off you need to check the laws in your state pertaining to holding someones personal belongings and what you are and rent allowed ot do with them. Also have you been paid in full as of this point for your invoice for handling the contains? I would probably start with an email to the adjuster on the claim and cc the insured stating the situation that the insured doesnt want the contents delivered back and yet the insurance company is no longer paying the bill so who is? Then if is legally allowed in your state I would send a certified letter to the insured letting them do they have X number of days to either sign a storage contract with you at X per month that they are willing to pay or they have until X to come and pickup their items. Depending on the laws in your state you may also want to talk with an attorney that is familiar with this type of situation.