Once again on the phone with Delta for several minutes because the damn website is charging me double mileage for an award ticket - and now, the latest - it's not listing redeposited mileage. This has been a recurring problem for a few months now.

When booking a award ticket that uses a split of lower mileage and higher mileage (ie 32.5k miles) a separate 32.5k is also deducted. This is listed on the mileage ledger as a award ticket without a ticket number or itinerary. I've seen this 4 or 5 times now. A total of 65k is deducted. It requires calling the Diamond Desk, explaining it to them and having them contact SkyMiles to give the miles back.

Also just did a refund last night for 62.5k and it's nowhere to be found. Delta people insist it's been refunded and the mileage credited back - they even sent me a screen shot of their program showing it. But there's nothing on my summary to show it - and it seems my mileage amount is a little lower than it should be.

Point is...just make sure you're really checking your balances closely before you use or redeposit miles. There are clearly some major deficiencies with the site and you might just lose tens of thousands of miles for a double charge or non-credit if you're not aware.