Go over to Amazon.com and enter code MP3S4ALL. Then the credit should show as a $2 MP3 credit on your account. You can use the credit towards any MP3 purchase on Amazon.com. The offer is valid from June 12, 2012 through June 15, 2012. You must use the credit by June 15, 2012.
I got my credit today, go and get yours while you can.
Thanks, Money Saving Mom