Thanks for the explanation. I'm glad to know the credit card agencies don't just blow off the consumer, but hate that it makes it easier for the devious consumer to take advantage.
You're not going to believe this, but I went to Walmart, with my lone receipt, and a copy of my bank statement, and talked to the manager. He said there had been a problem that day, and I wasn't the only one with duplicate charges, and he refunded me on the spot. Wow. I so did not expect that. I still think the bank shouldn't shove it off on the customer.
The road to success is always under construction.