I've charged back everything from erroneously issued parking tickets to flights canceled due to weather.
Every time, the credit card company immediately gives me my money back, settles with the merchant on my behalf, and I have always won.
The question is, who is giving the money to the banks that allows them to take this kind of a loss? People who have credit card debt???
The money comes from the business. The credit card company simply removes the money from the businesses bank account. This is one of the reasons it is so effective. Sometimes even mentioning the word "chargeback" when dealing with customer service will work wonders.
Banks require merchants to keep a certain amount of money as a deposit with them, specifically for this. The amount varies depending on the type of business the merchant is in (and the size and reliability of the merchant - for example Walmart is probably not required to keep any amount at all).
Strange world!