If you have enabled the Discount 20% category means you are willing to make a 20% discount offer to any FiverrBox member wants to order your gig in Fiverr.
So, follow the rules:
The buyer contacts with the seller in FiverrBox through Message system and they both agree how the seller returns 20% of the orders payment.
Then the buyer orders in Fiverr and after the delivery, the seller pays back the total discount.
After the payment back, the buyer leaves the review about the delivery of service.
The reviews are very important for a seller and for the service itself. That is the reason sellers try to deliver an excellent service. It is very important buyer leave a positive review.