If you are referring to entry tickets you should be emailed a confirmation of your purchase which will include a barcode. Once at the park you go can go straight to the gates, the attendant will scan your barcode, give you a physical card and scan in your fingerprint. If you purchased tickets for multiple days you will need the card and fingerprint each time you go to the park.
Disney springs has a guest services office however I am not familiar with the vouchers you are referring to. I would venture that they can take care of it for you, but if not they can at least point you in the right direction. Good luck
Disney customer service is second to none.
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