So, I did a dumb, and now I don't know what to do
I guess tech support is the most appropriate flare, though I don't expect much of a fix. I'm not sure.
I bought an outfit on the online store, and sent it to a character. Upon attempting to place said outfit in the dresser/armory, I discovered that I already OWNED that outfit. And.... yeah. I don't think SE's support is gonna let me trade it for something else, assuming I'm even able to get in touch with them, but I don't know what to do with it now. I think I just wasted $12 on nothing.
EDIT: You know, I once did something similar in WoW years ago. I bought a pet from the shop that it turned out I already owned. Contacted support and they let me change it to a different one. I guess that's one thing Blizzard has had over SE. Oh well.
EDIT 2: found the in-game contact option and submitted a ticket. We'll see what happens!