Checking inventory for Prestige class award tickets on the Korean Air website is simple enough -- in my experience they are few and far between. I've noticed that the offer to purchase economy and use miles to upgrade (in the same transaction online) is widely available. So I searched for a routing and date and went through the process to purchase two tickets. No problem with the ticket purchase.Then the system is to take you to the part of the transaction to where they take the miles and some more money and process the upgrade. Turns out, inventory is no longer available. So I cancelled the purchase.

Tried the same purchase again. Inventory once again shows as available. Purchased the tickets again -- and inventory is no longer available. Cancelled the ticket purchase once more.

Tried a new date, same routing. Same drill. Inventory shows available. Purchased the tickets and guess what? You're catching on -- no inventory for the upgrade.

Is this just phantom inventory? Is it a website problem? Should I call to try to purchase?

Appreciate any insights you KE experts could share!