Photographer issue- can you dispute credit card charges on something like this?

[AngB]

So back in August a photographer that broke off from a partnership we'd used before posted (word for word) on a FB group 'Just a few spots remaining if you are still looking for a place to see Santa ____" with a iink to book. (___ is a well known Santa in our area that gets booked like 2 years in advance between photographers,etc.) It was more than the average price but things were starting to book up and I liked their backgrounds so I booked it. The actual pictures were today. They had 3 different sets including one indoors we couldn't see that they were doing last *where we assumed Santa was*...(the set up we did a few years ago was set up the same way, one area with Santa and then a few other spots)...so after getting 4 kids ready for pictures and doing a few minutes at each set...find out at the end that there wasn't Santa. We talked to the photographer and she tried to act like I had booked the wrong thing, but another family was talking to her at the time about the same thing, and then DH overheard her saying to her assistant that almost everyone had been expecting Santa...so obviously not just us. (She has a session this evening in the same location that *does* actually have Santa but they were all booked.) I *never* would have paid this much to take some pictures at a random barn with some random fake Christmas trees and couches, but getting ready is a hassle and DD was pretty cute so....I think I'd be okay with some money refunded, if the photographer will agree to that. I have managed to find someone with a last minute opening next weekend that my friend already used that has a pretty good Santa (DD is 2 and really getting into Santa so I'd really like some cute pics of her with him besides malls/etc.), so I'm also okay with not getting any images and getting a full refund if they can't agree to anything else. Her assistant seems more reasonable and understanding (but they are swamped doing 5 min santa sessions all night so I doubt I hear from them anytime soon.)

Ugh, I'm so frustrated we have to do pictures again. DH is already refusing so I guess it will just be the kids for all of them which is ok.

WWYD? What would you ask for? I paid through their website using a credit card so I am very tempted to dispute it with our CC company but I'm not sure if that actually will work. (Mastercard). Obviously I can try to tell them that after discussing it we would just like our money back but I doubt they will do that.