Last week I flew AF from MSP to CDG. I was originally booked in premium economy A class, which as a round trip ticket with several other segments not of consequence here, cost $2500. @ OLCI I accepted a cash offer for an upgrade to J ($392) and was reissued into "O" class, of course this is a non earning class on AS. In fact it's a "standard award" fare class on AF

What are the chances of a successful argument to get the miles credited to MP for the underlying A fare? I have a good paper trail for the original ticket and upgrade transaction.

If nothing else I wanted to post this now so other members are aware of the risk of accepting these cash upgrades. I'll submit my request to MP next week for the credit and post back the result but I'm wondering if others might predict what I can expect.