Leonhard,
sorry for the bad experience you had and if you can see in posts over here on the forum, it seems they delete the bad reviews.
Now there are companies who sell Discus, that are close to perfect, do things go wrong? o yeah sure, but as a seller you need to try to solve those problems in the best way (where possible)
If you look here:
http://discusfishstore.com/catalog/reviews.php you can see perfect is possible and I can guarantee you there is not messed with those reviews (heck don't even know how to do that lol)
Hans