Walmart Walmart.com Walmart.com has been hacked Internet

I recently got a confirmation for an order from Walmart.com that I never placed.
The order was for a Birthday Cake Walmart eGift Card for $100.
I do not understand how it went through unless they do not look for the CCV or if they kept that on file. I went online to walmart.com to look for a telephone number to report the fraud, but none to be found. Their instruction was to call my credit card company, to change my walmart.com password, and to e-mail them. I did all three and had to call my bank to re-issue a new credit card which will take 7 to 10 days. The response from Walmart after 3 days of emails is they would credit my account $60 (so I am out $40) and this had never happened before. Now looking on the internet it sounds like this has been happening for quite a while. I saw the $100 charge show up on my credit card so I have contacted my bank to dispute the charge. All I know is I am not going to do business with Walmart.com any more unless they at least be honest about being hacked.