It's no surprise that Walmart/Sams Club will not accept ApplePay. After the Target fiasco Walmart has built their card acceptance around the upcoming EMV (chip) cards. Check out the terminals in Walmart and Sams: they allow for a chip card to be inserted at the bottom of the front panel. EMV chip cards are more secure than a traditional debit or credit card and has a chip that has a ever-changing value which makes duplicating it very difficult.