I Think that it is an automatic charge on asset allocation opposed to the difficulty of the charge. I was concerned about that too when I noticed my Amex was "pre-charged" on apr 10 when I bought it at 2:03am CST, but then noticed the billing address for the card they had was my work not my home address i called the next day to correct and things should be fine. All that said, we may be the only two with odd payment things of the hundreds here waiting for confirmations... i really cant imagine that is it.
Also, for you they already have their money from the gift card... The AppleCare they can treat separately... You should be one of the easiest. Good luck and stay confident.