I think, paisapay should take all precautions while accepting payment by credit cards. Verify buyer's identity etc. whatever is within their means. Then post money to seller's account which should be irreversible under any circumstances for chargeback, if the seller produces all proofs like shipping and POD. Then send this money to seller within their normal cycle.
Only any kind of lack of service/product should be liable to be investigated for and if found true, consequently chargeback the seller.