According to IMDB it doesn't exist on R2 DVD, although that is just the amazon advert on the side. Maybe it exists but amazon don't sell it. IMDB seems pretty authoratative though. I haven't bought a halliwells since I found it.
Try Ebay. If you don't find it keep looking. I bought a film recently which had never been put on dvd and you can't get it anywhere in Europe, in Australia. Region 2 and everything. Everything comes to he who waits