As far as i know, in China clothes work different and you can upgrade them with additional fragments, but their initial stats are lower than in other regions. PProbably that's why game allows for buying them.

And no, there is no way to use those extra fragments or get back coupons. Remember golden rule here: if you mess up, it's your problem. If Oasis messes up, it is also your problem.

Hello,
Generally an error of this nature will not be reimbursed. We advise caution when buying items to ensure that they are the correct item you are looking for. However, you can try to submit a ticket to the in-game CS platform to make an appeal for reimbur*t since you do already have the outfit in question. Here is the link.

https://support-center.oasgames.com/

Thanks and good luck!