As I mentioned earlier, PayPal reversed my charges and refunded me that same day, my money cleared today. I got an e-mail from iTunes support informing me of the refund of the $20 in credit I already had on iTunes when this all happened. They gave me a transaction/confirmation number, but I haven't seen the money returned to my iTunes account yet. They did say it would take up to three business days to credit, so we'll see.
All that aside, I have to say that the Apple iTunes customer rep I dealt with was very professional, deferential, apologetic, and genuinely cared about my issue. He really took ownership of my problem and saw it through to it's resolution, even sending me e-mail updates throughout the process without me contacting him first.
All too many times, companies get hit for the bad things that happen, and they should. But I also believe it's only fair to give as much attention to them when they go above and beyond to resolve your issue. As misanthropic as I am, I was very pleasantly surprised.
One final thing: there was one thing that caught my attention in the final message from iTunes support that gave me pause:
"A refund for order number XXXXXXXXXX has been issued toyour iTunes account. If you notice that the entire purchase amount of $106.99 (instead of just the $20.12) is returned to your store credit balance, please reply to let us know. You may have to sign out and then sign back into youraccount in order to see the credit posted. Please note that this is a one-time exception to our sales policy. "
While I'm happy with the outcome, I'm concerned about the last line in this quote: I didn't do anything wrong, didn't do anything that was outside of their iTunes security policy, the purchase was proven fraudulent and acknowledged to be so. Then why make it seem as though they're doing me a favor by refunding money that should have been there in the first place? The sad thing is, in the terms and conditions, they have a statement that they're not responsible for loss as a result of fraudulent or unauthorized purchases.
This is why I'm going to always use a prepaid card, and like a previous poster suggested, never keep more than $15, the minimum denomination iTunes card I can purchase. Lesson learned.