It really doesn't matter how you or others "consider" this transaction, the credit card companies have taken the position (right or wrong) that the transactions (sales and rebate) are two separate actions. You made a purchase using a credit card, the card company is required to provide protection as a part of that transaction. You then filed a rebate request with the merchant, totally separate from the purchase (and not a condition of the purchase). You can either accept that as a fact, or you can decide to challenge it. If you do challenge their decision, you will have very probably have to take them to court.
One thing to consider in this... Do you agree that you can't get your money back (from the credit card issuer) AND keep the merchandise??? If so, who would you return the merchandise to?? Remember, the merchant is no longer in business and obviously not accepting return shipments. And if you believe that you should be able to keep the merchandise, you need to be aware that the credit card issuer will NOT give you a credit while you keep it.
As for your other issue (Cityspree gift certificates), I would suggest you start a fresh thread, since this thread is already a 'carry-over' from another.