From my understanding, Sam's Club has independent contract Doctors. When you pay for an eye exam, you're paying the Doctor who really has no affiliation with Sam's Club. Sam's Club just gets money out of contacts and glasses. When Doctors leave a place like that, they generally bring along all their patient files with them. The new Doctor starts fresh. I can understand why you would have to pay for another exam because it's another Doctor, but Sam's Club is usually known for customer service and I would have went to a store manager. It's kind of late now.
If it isn't already too late already, find out where the Doctor went to and try to have a follow up in his new location. You paid him. You also should have let Sam's Club know that you were sick otherwise it just sounds like you're making excuses.