Returning Books on Audible

I cancelled my audible subscription a month ago because I've been reading more on my Kindle, but just accidentally purchased an audiobook while trying to get the Kindle version. Is there a way to return this? When I go to return it in Audible all my other books have a "Return this title" option but this one which just says "Order processing." Not sure if this is because the others were Audible credits while this one was with card or just need to wait until the order has been processed?