I did this last Sept. at MK. Was at WDW for the weekend with my son and spent our day ay DS. I needed to get embroidered mouse ears for my daughter before going home (can only get at MK). We went up to the customer service window (had to wait in the line with those purchasing tickets) and explained that we wanted a shopping pass. We had to buy our tickets and the CM gave us 1.5 hours in the park. We made our purchase, walked around a bit (son wanted to see the Partners statue) and then returned to the window where I received a credit to my credit card in the amount of the ticket price. The CM did ask if we found what we wanted to buy, but didn't ask to see it. It is important to keep your receipt, can't remember if that's how they tracked when we bought the tickets or what, but I did have to give it the CM in order to receive the credit.