Flex pay mix up

Hi I tried to order an item and tried to pay by flex pay. The money came out of my account right away. But then a second later I got a noticed saying I wasnt eligible for flex pay and a letter will be mailed to me. Just as I tried to get out of that page more money was taken from my account in the full amount of the item. I didnt know what to do. I was shocked. I did manage to cancel the order. But my questions are: If a person can order something at 2am and money is quickly taken at 2am then why dont you all have costumer service available at 2am?
And why dose it take so long to get a refund and it dont take that long to take moneies out of your bank account?