Is such a cash pick-up document binding?

Hello at Mediamarkt I want the laptop, she gave it to me and told me to pick up and pay for the goods at the cash desk…

Now I was almost at the cash desk and I had a lot of cash and cash machine has a limit… On account they do not make it so I went home and agreed (verbally) I should come back with money and this note on Monday… (Today is Saturday, therefore I can't withdraw money, not that much at least) now I'm at home and browse the MediaMarkt online shop and see a nice offer… Is this paper binding? Or I can throw it away and order something online

It says "voucher only valid with the associated receipt", means if you have not paid for it and no receipt is also not valid. If the whole thing is not valid, it can hardly be binding.

Nowhere does it say that you commit to buy this.

However, an oral contract may be valid. A contract is only a declaration of intent by two parties, no paper is required for this.