Some Amazon users discovered on Friday that saved Apple Card numbers had been removed from their Amazon accounts. CNBC confirmed with two separate Amazon accounts that an Apple Card used to make a purchase on Thursday had been removed as a payment option on Friday.Amazon said it has not intentionally removed Apple Card as a payment option, and blamed the problem on a bug. “We are aware of this technical issue and are actively working to resolve it as soon as possible,” an Amazon spokesperson said in a statement.Apple Card was launched last year as part of a partnership between Goldman Sachs, which functions as the bank and lender for the card, and the iPhone maker, which built software for it in the Apple Wallet app and markets the credit card to its customers.Apple didn’t immediately return a request for comment.While Apple Card is designed to be used for contactless payments with an iPhone or online purchases though the Apple Pay system, it is a Mastercard with a credit card number which can be used like any other credit card.That’s how Apple Card holders can pay for purchases on Amazon with their Apple Card. Amazon does not accept Apple Pay, Apple’s payment service.Last year, Bloomberg reported that card networks have designated the Apple Card as “elite,” which means that it collects higher interchange fees per purchase. Those fees are paid by the merchant, who often feel they have no choice but to pay higher fees for “elite” cards. Mastercard has an arrangement where stores can’t turn down elite cards with higher fees while taking other Mastercards with lower fees, Bloomberg reported.