Songdogs Howl at the Moon!
The Amazon.com Customer Service Phone Number is buried on their web site if it exists at all. They want you to force you to send an e-mail instead. When my e-mail went two days without a response, I tracked down the number. The main number for the Amazon Customer Service Department is 1-800-201-7575.
If your problem is with a digital download like an mp3, they will switch you to another person. You'll have to wait again.
I do have to say that my problem was solved and it only took about 15 minutes with most of that being time on hold. I would suggest calling them on a speakerphone if you have one available. That way you can do other things while waiting on hold. Their people were pleasant and were helpful when the problem was explained.