On 5/1/2015, I had 5 out of 12 Walmart transactions post as debits. You have to keep close track of your credit transactions or you may be short on your rewards checking account requirements. Look at your receipts immediately to verify they were credit and not a debit transactions (especially Walmart). On the Walmart receipt, look for the TOTAL. The line under the TOTAL will say DEBIT TEND (debit) or MCARD TEND (credit). I have only experienced this at Walmart. Sometimes, they do not give you the option to use it as a credit card. It automatically processes it as a debit even though you press credit card. There is no way to cancel it. You would have to go to customer service for a refund. It did the same thing at self-service and the cashier. The cashier and the self-service attendant could not make it process differently either. It was not debit card or bank specific. I used different 4 cards for 3 transactions each as usual. 5 of the 12 transactions were processed as debits. This is the first time I have had this problem at Walmart. They may have changed something about their system.