will iTunes use my gift card first before charging my credit card?

Well NO.

I use 2x$50 iTunes Card yesterday so I have $100.

But Apple say I must pay them $30 on my credit card.

But they other day I buy too 2 iTunes Credit card of $50 each.

And when I activated both, I just received $70.

I really don't know what happen.

And sure no email to ask to Apple.

And my english is crap.

It looks like you had an outstanding charge for $30 on your account. When that happens, you usually have to enter in valid credit card info to pay for it or redeem gift cards to cover the amount.

In your case, as soon as you redeemed the cards, iTunes saw that the amount you redeemed was sufficient enough to take care of that $30 outstanding charge and so it subtracted it from the $100 you redeemed the gift cards for.

If you have any other questions you can contact iTunes Support via expresslane.apple.com

Yes, whenever you redeem an iTunes Gift card, whatever purchases you make will use the gift card credit first and then once that credit is gone, it will use your credit card for purchases.

Yes, as long as you don't gift anything or buy gift cards or certificates.

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