Advice Needed: Client disputed credit card charges for wedding I covered out-of-state over the weekend.

I booked a last minute wedding in another state this past weekend and had the client fly me out for the day. Contract was signed prior to taking the gig. This morning I get an email saying the client disputed the charges with her credit card claiming it was fraudulent charges. This came out of left field as she was super happy with the everything. I have not sent the album yet. Has this happened to anyone before? What steps can I take?