Bags don't always make it on planes. Yeah, it sucks. And you'd think with a pink tag they'd do better than with regular checked bags. I'd expect a handful of miles to be tossed your way by Delta CS. It's only been two days since you submitted your complaint. Average response is a couple of days, sometimes faster if you're a high tier Medallion. If you haven't gotten a response within a week, I'd follow up.