I think looking at that letter the meaning can go two ways, your oldest retail revolver that they internally compare to the Wally MC benefits is too recent. That's how my mind is thinking it through but what card could they be comparing it to since the ninkipotes didn't say 
I would get on with Credit Solutions and say define this message and reconsider unless you originally called CS to get the increase instead of the Luv button (it hates everyone not just Chris)