Lost your ticket(s)? No access to your mailbox? Your tickets got stolen? Follow Get in touch with Ticketmaster. Keep your order number to hand. Related articles Can I upgrade my day ticket to a combi ticket, or exchange it for a different day ticket? My festival ticket is in someone else’s name. Can I get in? Opening hours How do I exchange or upgrade my tickets? Where can I safely sell my tickets if I cannot come to GMM20?