I wanted to use a credit I had (refused boarding credit, not cancelled flight) for my ticket and use miles or straight pay for my wifes ticket. They told me I couldn't because they cant do two forms of payment. This doesn't make sense to me, my credit was short $85 and they took a MasterCard number for that.

By not letting me put my wife on my reservation, she cant get preferred seats or get a first class upgrade. That essentially means I cant either, I want to stay married more than I want a better seat.

Is there some trick to add her, seems like this is unreasonable, it means anytime you use miles or flight credits you lose part of your preferred access.