Delta's reply:
Thanks for writing. After reading your email, I certainly understand why you wanted to let us know about this situation. We expect our gate agent to be helpful and professional at all times. I agree that your travel plan was disturb as your baggage delayed. I’m really sorry you didn’t receive the service you expected and should have received.
Bonus Miles
As a goodwill gesture, I’m adding 7,500 bonus miles to each of your SkyMiles accounts. They should be transferred into your accounts within three business days.
Your loyalty to delta as a SkyMiles member is greatly appreciated. We look forward to serve you better in future.