Call your credit card company immediately and find out if these are legitimate or a hold. If not then verify if they are real and if they are not then dispute the charges. Contact Princess and let them know of the error and that you did not make the charges, they were added after the final bill and that you have disputed them with your credit card company. Make it clear that you did not make the charges and you want them removed.
Take care and let us know how it turns out.