If the buyer chooses to do a chargeback on their credit card, the CC company will refund them the $$$ while they investigagte... Once you prove that you shipped what you said you would, when you said you would, the credit card company will then charge the buyers credit card again. You will not lose anything, as long as you do not keep the money in your account. If you do, PayPal will freeze the entire amount while it investigates.
But someone cannot just charge something back on their credit card. They need to have a good reason with proof.
🙂