Credit card on file

Question

When I purchased Mac OS Lion, I entered credit card information. I thought Apple discards my credit card info after every purchase. So then months later I wanted to use an app store gift card and I clicked on the "buy" button before entering the gift card code thinking that it will ask me for that at checkout. The next thing I know, the software is immediately and automatically downloaded to my computer! I was surprised! Turns out Apple went right ahead and charged the credit card on file. I emailed them and said "whoa, whoa whoa, don't that!!  I have a credit card on file with amazon.com but even amazon ASKS me how I want to pay at check-out time! I think it's sneaky of Apple to not ask me how I want to pay!" So they credited my credit card account and I now learned how to register the gift card so that my app store account now has my gift card $ value in the system for me to use at my next purchase. Since then, I went to my profile and permanently deleted my credit card info so that Apple doesn't "conveniently charge my credit card again without asking me".
Another sneaky thing that Apple does is that the cost of the app does not include tax thereby making it difficult to spend say a $15 gift card for  a $14.99 app. You still have to spend out-of-pocket money for the tax. Even if you were to choose an app that costs less, with tax included, you now have something like $1.75 left over on the gift card which you can't use for anything unless, once again, you spend out-of-pocket money. Basically, Apple doesn't allow you to make "neat" purchases. One way or another, it makes you spend more. Please understand this is not an issue of me being petty. I just don't like it when multi-milion dollar companies steal pennies from me when I try to buy something.
Anyway, my question is this: even though Apple credited my credit card, I still have the app in my computer. The Apple customer service rep said I can re-purchase it using my gift card. Why would I do that if I already have the app on my computer and my credit card has been credited? Doesn't Apple know that I have the app already? How do I "return it"?

Answer 1

Apple is not being sneaky. You are just uninformed about how things work in the iTunes and Mac App Stores. Nowhere did you read anything to lead you to believe that your bank card information would be discarded after the first use. That is something that you made up in your head.
The tax situation in the USA is different than most other countries. Here in Mexico, as well as many other countries, there is a federally mandated tax of a given percent of the purchase. That tax is nationwide, so wherever I may live in Mexico the tax is the same. That is not true in the USA. Every state and even every city can levy its own tax on the sale, so the price of an item plus the tax will be a slightly different total everywhere you buy the item. For that reason the prices in the MAS do not have the tax included. The tax is added at check out when it is established where you are located and the tax for your location is applied.
The reason that Apple expects that you will repurchase the app with the gift card is because Apple is expecting you to be honest. You were ignorant of how to correctly redeem a gift card and the system charged your bank card on file. Apple has credited the charge to your bank card because you have complained about your own ignorance of how the system actually works. Apple expects that as an honest person you will delete the app for which you have been reimbursed. Apple expects that if you still wish to have the app that you will properly redeem the gift card and purchase the app.
So at this point, the real question is - Are you an honest person?