There is a different entity specifically dedicated to supporting Yu-Gi-Oh! Duel Links.
In order to contact them please tap the "gear" icon found in Duel World to access the "Help/Etc. Menu" where you will find the "Contact Us" button.
You can also visit the official Duel Link website https://www.konami.com/games/inquiry/global/
At the bottom of the page you’ll find the “Inquiry” option where you can submit a ticket with them.