Copied from the Hellfest page:
TICKETS INFORMATIONS
POSTPONEMENT OF THE ANNIVERSARY EDITION TO THE 18TH, 19TH AND 20TH OF JUNE 2021:
KEEP YOUR 2020 TICKET!
ALL TICKETS ARE CONCERNED REGARDLESS OF WHERE YOU PURCHASED IT.
YOU CHOSE TO KEEP YOUR TICKET FOR 2021:you have nothing to do: the ticket dated on 2020 remains validyou can access the 2021 festival with a 2020 ticket regularly purchasedYOU CANNOT GO TO THE FESTIVAL IN 2021 AND WISH TO GIVE YOUR TICKET TO A FRIEND OR ANOTHER FESTIVAL FAN RIGHT AWAY:go to Ticketswap the only official Hellfest ticket reseller to sell your ticket with a private sell at someone you know or a public ad to the 26,000 people currently looking for a ticket to the festival.
With Ticketswap and only on this resale site, you have the guarantee of a trustworthy transaction between the seller and the buyer (the Secure Swap system cancels the old ticket, avoiding any risk of fraud, and the new ticket is only sent upon receipt of payment). All tickets purchased on Ticketswap are official Hellfest tickets. If your country is not on Ticketswap’s list, ask a friend to sell you ticket for you.
If you have trouble selling your ticket online, contact immediately Ticketswap for help.
YOU CANNOT GO TO THE FESTIVAL IN 2021 AND WISH TO BE REFUND (all types of tickets):You bought the tickets on the official Hellfest sale :From April 20th, 2020 to May 15th, 2020 at midnight (French hour):
Send us an email at billetterie@hellfest.fr with your bar code.
Be careful : After the deadline, no ask for a refund can be registered.From May 18th, 2020 to June 19th, 2020 at noon (French hour)
You’ll be received the process to confirm your refund request and erase your ticket.Since June 24th, 2020 (with bank delays)
Your refund will be credited on the credit card used during your purchase (in case of change of card since the purchase, please consult the Help topics below).You bought your ticket at Ticketswap:Please contact their customer service.You bought your ticket at Leclerc Clisson or with your works council :Feel free to get back to the selling point concerned directly.We will not be able to respond to any requests regarding tickets purchased at an unofficial resellers.
WE MAKE EVERY EFFORT TO RECORD THE REFUND OF YOUR TICKETS AS SOON AS POSSIBLE. THANK YOU IN ADVANCE FOR YOUR PATIENCE, AS THE CONTAINMENT OF OUR TEAMS MAY SLOW DOWN THE PROCESS
Thanks to Karajuju for showing me.