The paperwork we send in the defense response with everything it asks for in writing so it's a solid defense (we have all the evidence asked for when the chargeback papers arrive, why would it lose?).
Lets take an AMEX chargeback for example. I know these are the same for everyone since they all come from the same place.
The letter arrives and says something like:
"Our mutual customer has disputed the charge of #*$! dollars". Then there is an admin type reason like "goods not received" or, "not what they ordered", etc.
Then there is a section that asks for us the merchant to document something like "send signed proof with signature that the goods were received at the shipping address on the order", give a "copy of the order", send "charge receipt with approval code".
So we send in a signed bill of lading with the address on it, or if they did not get the item as described then they have to send it back with signed proof that we received it back. When we get it back we either say it was or it was not, if it was we print a copy of the online return policy and fax it to AMEX asking for a restocking fee plus shipping. If they think it was I hope they remembered to take a picture of it and the photo they saw when they ordered and explain how it was different (most don't remember for some reason).
Some like to chargeback when the receive damaged items rather then deal with cooperating on a freight claim, you can usually tell when they don't want a replacement. If we get it back damaged a photo of the damaged item can be taken and faxed to AMEX with the response. They can file a claim with the carrier to get refunded cost of the item. One customer tried this and had a lawyer send a letter a year later saying that since we did not ship back the damaged item we received from the customer we needed to do a refund. But they could have had it picked up, why would we pay shipping back. Why would we hold a damaged item for that long? Perhaps you would like to pay a years worth of storage fees? (not too bright).
Fax the documents in by #*$! date. They also allow you to write a letter back, but this only needs to be done if some evidence is lacking or not available for some reason. It's not a heated conversation, it's a clear rebutting to the official chargeback reason listed.
The customer can also rebut again and it can go back and forth 3 times or so with a month or so between each time but rarely does. In those cases each gripe is dealt with the same way. In some rare cases emails can be submitted from the customer to indicate that they did actually receive the item, or what the original gripe was. There are also dates on the email. For those who like to call early and threaten to do a chargeback, an email can be sent asking for specifics and later used against them.
In what situation would you lose given the above chargeback if you had all the info. asked for with your order?