Although refunds are given by Steam for games purchased within a 14 day period (and if played for less than a 2 hour period), Faeria's in-game items are not refundable.
This is as per the notification when purchasing items in the Shop:
And covered by the following paragraph in Steam's own refund advisory page.
Third-party developers will have the option to enable refunds for in-game items on these terms. Steam will tell you at the time of purchase if the game developer has opted to offer refunds on the in-game item you are buying. Otherwise, in-game purchases in non-Valve games are not refundable through Steam.