Yes, they'll issue new ones. I don't know if it matters, but this last trip I still had a few days left on my room key/tickets so when I had the cm change them to no expiration I also had him make a copy of them so just in case I misplace them I'll have my copy so they can be replaced. Of course I have to put the copies in a place that I'll remember too! Also, if you have the paper tickets keep your receipts or write down the number on your tickets, because if you lose those they can still cancel the lost ones and reissue them from your original receipts.