I haven't ordered from them, I have heard that he might have had a bit of trouble back in August but lately I have been a bit out of touch with the "offline" homebrewers. Maybe shoot a question into the "Japan Beer Times" forum if you still cant get ahold of him. That forum is manned by people who know the owner of Advanced personally and they might be able to let you know whats up.
Wort (immersion) chillers are easy to make, I recommend making one over buying one every time! However the first thing you should note is the length of any chiller if you buy it, the surface area and the speed which it chills depends on it. Its super easy, go buy a coil of small diameter copper pipe, (I got 10 meters it seems that is standard package size). Once you have the pipe in hand at the hardware store, go to the section where they sell tubing and attachments for garden hoses to faucets. Get enough tubing to run from your faucet to your pot, and another section from the pot to the drain. You will need 2-3 hose clamps to make sure the tubes stay on the copper pipe. Slowly bend the copper pipe into a coil leaving enough on the ends to go up and "gooseneck" over the top of the pot. You want the hoses attached a little distance from the pot and DEFINITELY on the outside of the pot! This prevents accidents, leaking cooling water into wort could contaminate it... Lots of tutorials on this site though, check em out
Another note if you are using a chiller for the first time, turn the water on SLOW, full blast through a small diameter hose will likely blow it off the pipe and you will have water get all up in the wort. I flared the ends of mine a bit so the copper hold the hoses a bit tighter. Yes I made that mistake one time