Question about order cancelation

About an hour ago, I bought currency for this popular game in Roblox called Jailbreak in hopes of getting a head start but when I started playing, I noticed that the game is a laggy and is sometimes unplayable so I wont be able to use the currency that I bought.

The seller have not delivered my item yet but it’s too late for me to cancel the order because the cancel button is long gone so I sent him/her a message asking to cancel my order and gave him a reason why.

If the seller doesn’t cancel, what can I do?

I’m assuming this requires person to person trade? If the seller doesn’t cancel there should be a dispute button. If this is an automated delivery of a code, this might be more difficult to get your money back as its harder to prove you aren’t just going to use the code after receiving refund, as they’re providing everything they should, but you just aren’t able to play the game (something you should have confirmed prior to buying)

If it is the first one, it should be easy to get the order cancelled / money refunded.