Refund

Hello,
I purchase a trinket with coins can it be refunded ?

Sure, if you bought the item by mistake, you can use the item misbuy category here: https://www.warmane.com/account/support?do=new

Within 24 hours of using the Coins, that is.
The option to refund isn't some "try-before-you-buy" thing for people who regret the item they got later.