***This does not cover how to win a fraud case. Where the customer used a stolen card or PayPal account.
I see the matter of many people getting hit and losing with a PayPal dispute. I have never lost a dispute yet and they have ranged from $10 to $1500 (some nonhosting related).
Method 1.
Gather evidence
* I seriously suggest you add a script to grab the users IP address on your site when logging in. This can be provided to PayPal for them to check their registration and common usage tables. If the IP addresses match, you will win instantly.
Call PayPal. DO NOT EMAIL THEM.
* Many disputes are lost because one side of the dispute sends a wall of text to the support agent. If you call and interact with the support team, they will hear the sincerity in your voice and they will see you as a human instead of a text message on their screen. ACT KINDLY AND RESPECTFULLY. Explain your situation and why it is an attempt at scamming you. Provide a tracking number if the item was physical. If it shows delivered, YOU WILL WIN.
What if my item was virtual?
* Be sure to add a section to your ToS (Terms of Service) stating that refunds are allowed if given the approval of staff via support ticket or email service. Any unauthorized chargebacks will not be granted and you will be blacklisted from our service.
When they check out and agree to your ToS, PayPal will see they agreed not to perform an unauthorized chargeback and will side with you.
Method 2.
"Suns out, Guns out".
If non of the above methods have worked, call PayPal, yell at the first rep you get connected to and ask for their supervisor. Keep going up in the customer support ranks until someone with authorization will override the dispute and cancel it.
What if the dispute is closed and I lost?
CALL THEM. THEY CAN REOPEN A CASE WITHIN 30-90 DAYS.