Sounds like a rogue GA.

What you did has been done a number of times by various FTers and other members.

Unless they're starting to crack down on this, the Y class part plus the "red flag" comment makes it seem like a GA did it and reported it.

If this really is legit, the proper thing to do would be to flag your record, page you to the gate, and offer to re-insert your OP number to retain your upgrade, or downgrade to Y. That's what a COmpany touting "grrrreat customer service" should do in such a situation.