It does sound like the property has messed things up here. It may take a lot to fix it. First, they should have closed out each folio separately. Using a single payment flagged the back-office to think it was a single stay and they processed it accordingly. Also, it has been reported that some properties do not credit stays when someone other than the registered member settles the bill, regardless being a spouse. Unfortunately, FDCs get pretty good about determining what response will result in them having to do little, if any, extra effort regardless of the outcome.

it's a shame SPG doesn't see the issue here, but it sounds like you're going to need to work with the property to get things squared around, if they are willing to do it at all. And be very specific what outcome you want. I know I have advised people to do exactly this same thing, but it is pushing the T&Cs and there are going to be some thinking it is simply wrong.

Good luck.