Unfortunately, cases like this are user error - The Auction House does not have a bug like what you have described.
Auction house purchases are not refundable by the support team, as the gold is already in the hands of the person selling the item you purchased - it's not fair to them to confiscate the gold because you regret your purchase.
I'd recommend re-listing the staff for what you paid for it, or as much as you feel you can get for it.
Regarding scammers - Please remember that diamond gifting is not an approved transaction method, and is done at-your-own-risk.