Can I Appeal a Lost Chargeback Through PayPal?

Chargeback
A chargeback takes place when a buyer asks that her bank remove a PayPal charge from her bank transaction or her credit card statement. One reason a buyer may request a chargeback is that a third party discovered the buyer's PayPal password without authorization and used her account to make purchases she did not authorize. Other reasons could be that the seller did not deliver the merchandise the buyer ordered, or the merchandise that the seller delivered is not the same merchandise that the buyer ordered.
Procedure
PayPal notifies you as soon as possible when it receives notice of a chargeback. PayPal places a hold on the funds in your PayPal account that are related to the transaction at issue while the credit card company investigates the chargeback. You may appeal the chargeback during the investigation phase by providing PayPal with information it can use to dispute the chargeback; however, PayPal is not obligated to dispute the chargeback on your behalf. As of the time of publication, the email address PayPal provides for evidence to dispute a chargeback is chargeback-response@paypal.com. The investigation may take up to 75 calendar days to complete.
Decision
The buyer's credit card company, not PayPal, decides whether the chargeback is justified. PayPal cannot control the outcome of the decision. If the credit card company decides in the buyer's favor, PayPal must return the funds related to the transaction to the buyer. You cannot appeal the chargeback. This is the process you agreed to when you agreed to the PayPal user agreement for your PayPal account.
Avoidance
Most chargebacks occur in the context of online auctions. Therefore, PayPal offers guidance to auction sellers on how to reduce the likelihood of a buyer implementing a chargeback. PayPal recommends that you document the condition of an item before you ship it; that you retain copies of correspondence with the buyer; that you use a delivery service that provides proof of delivery; and that you communicate your return policy to the buyer before transacting business.