I flew Delta/Air France from TLV to LAX. Our luggage was delayed over a day so I bought my baby new stretchies and filed a claim, submitting the receipt. They sent an email saying they need the receipt and I replied I sent it to them already and then sent them a second email with the receipt. They closed my case claiming I didn’t have the receipt. I responded several times by email and got no response. Then I tried calling and they said all correspondence needed to be by email. I’m not sure my next step. Can I file a DOT complaint?