What the crux of all of this arguing seems to be missing is that people are talking about two different beasts here - a miles-earning credit card, and a miles-earning debit card. With a credit card, your returns should always be put back on the card - that is part of the merchant agreement banks set forth to places who wish to accept credit cards.

With a debit card, though, it's a different manner. A lot of places cannot process a debit return - their systems just won't allow it. And since a debit card transaction is technically equivalent to cash, people will tend to get upset when they are told that to process their debit card refund by credit card, it will take the standard credit time - usually 5-7 business days - for the refund to post.

Hence, at places such as Home Depot or Wal-Mart, you will generally get a cash refund on a debit transaction, because in their eyes, you paid cash in the first place.

This is not to say that I condone the massive purchasing of items via debit, only to get a cash refund and miles. There is still a merchant fee to be lost by the retailer (albeit a smaller one using a debit system). And ultimately, it will get paid for in higher prices.

Mike