I also bought the OS from 3ds-flashcard and have still not received any email or confirmation. It still says that it is in preparation and I have already tried contacting them as well.
A lot of people like to fault Gateway for their practices but for a while they were the only solid option available on the 3ds until the shitstorm happened with all the public cfw releases. TX knows what they are doing and spending $30 or whatever it ends up costing for the sake of convenience...