[QUESTION] How to win a Paypal dispute over SNAD?

Someone bought a script from an indian company for $750 and it seems like the quality of the code/product is not as good as it should be (Bugs everywhere, not stable, poor support), and all those bugs do not exist in the demo version for some reason.
Given that:

• The buyer cannot fill unauthorized payment claim
• The buyer cannot fill not delivered claim

Any ideas on how to win such a dispute?

by Yidir via TBN