Remove duplicate items from cart

hallo!

I need some help with a problem I am facing.

I would like people to order meal tickets which leads to a direct checkout forum. I have removed the possibility to look into carts because I want people to check out immediately. The only problem that remains is that if you accidentally leave the page and have to reorder, the client ends up with duplicates. There is also no possibility to delete the items you don’t want. Preferably I would like customers to lose their items if they accidentally leave the page so they can order with a fresh start.

How do I fix this? Is there a snippet or code I can use to fix this?
Or is there maybe a option in woocommerce I have overlooked?

ps: I do use the Woocommerce direct checkout plugin

Thank you all in advance,

Andi

The page I need help with: [log in to see the link]