My seller can’t finish work on time he asked me to cancel an order.
Service fees are added at the time of purchase where a buyer can review and accept the total amount requested to pay. These fees cover administrative fees. As of May 2018, the current fees assessed to the total purchase amount are $2 on purchases up to $40 and 5% on purchases above $40. When purchasing from your seller’s balance (i.e. out of your earned revenues) or buyer’s shopping balance (resulting from any credits or refunds) you will not be charged a service fee. Funds returned to your balance from cancelled orders will not include service fees paid.
This is from the Terms of Service which you will find at the bottom of the Fiverr main page.