diamondcat - it’s too bad that after purchasing NWA Delta didn’t carry over this feature to their own web site. Strange and sucky for us as it was a great time saver.... especially the hassle of trying to get through to an actual person on the phone.
I believe (if your not Elite) you have to pay a fee to re-deposit your miles back into your account. Their are a ton of experts on this site that can answer your questions about that.