As a general rule, once an order has been confirmed, returns or exchanges may not be made.
More information on this:
However, you may be able to return your item if.....
・The size or color of the item seems different than it did in the listed image
If you think so, you may contact the seller via BUYMA Message System
What do you need to provide the seller when you contact...
・Provide the images where didn't match the listing description
・Appeal details of the issue
What's the next step if the seller accepts returning the item...
Please ship the item back to the seller with tracking number. When the seller receives the item, we can cancel the order and issue a full refund back onto your payment card.
*It is up to your seller whether or not they are willing to consider making an exchange or return, so if the issue cannot be resolved directly, then please contact BUYMA Member Support at firstname.lastname@example.org.