Hi Guys,
I purchased two Delta Comfort Plus tickets, which are more premium in cost than regular cabin for slightly extra leg room. My fiancee and I decided to try and pool our AmEx points to see if we could upgrade our ticket to possibly first class with SkyMiles. When I called the agent I was surprised to find that "W" class, which all tickets purchased Delta Comfort are, is not upgrade-able. They said the only way to upgrade it would be to pay $900 to downgrade the ticket to main cabin and then upgrade from there.

It obviously doesn't make much sense to pay more for a ticket in a higher rated comfort class only to find I need to pay more to get a downgraded seat then pay more miles again since I have a lower tiered ticket. It should be such that it should take LESS miles to upgrade from the premium comfort to business class.
I guess I am wondering if this is some bug in their system that needs to be resolved?
Thanks in advance for any input!