Thank you for the clarification.

I used a reroll ticket, but I only got one result and was not given two results to choose from. Does that mean the buff had already expired or was not active at that time?

The buff only last for 1 hour from the moment you enable it

I know this is my mistake, but is there any chance you could return the 2 IV Reroll Tickets?

I didn't know how the buff worked, and I activated it by accident without realizing it would consume both tickets. I wasn't trying to use them, and I had no idea this was how it worked.

If it's possible, I'd really appreciate it if you could help me this one time. Thank you.

I apologize but unfortunately we have to deny your request for a refund. The NPC used to purchase the double reroll service displays the cost of the service before the transaction is completed. The transaction also requires navigating multiple dialogue windows, including confirmation prompts, before it can be completed. Posted below is that chain of dialogue:

 

As a general reminder, we recommend carefully reviewing all information presented during a transaction before confirming it. I know this isn't the response you were looking for, and I apologize for that.

I'll go ahead and close this thread now, and I truly hope you enjoy the Summer event.