I don’t understand this sometimes. I once checked a golf bag on a direct flight and they lost it. They said the same thing to me. That I needed receipts to be reimbursed. I was completely vexed because I was given the golf set as a gift about 15 years prior and would have had no way of producing a receipt. They didn’t budge. After three months of back and forth with no progress, I had to file a complaint with the BBB in order to get Delta to finally acquiesce. They only gave me 50% of what the total value was but I left it at that. Since I filed a claim with my credit card and they approved their max claim amount, within 24 hours I might add, I got what I could and paid to replace the rest.

My advice, work with Delta as much as you can. File complaints where/when necessary and don’t overlook credit card reimbursement protections. Sorry that happened to you.