There are indeed other products which are very similar to some of the Niteye range, but in the EYE30 (the subject of this review) Niteye have created a distinctive and great quality light.
Unfortunately a bad one has slipped through (or damaged in transit somehow) and it is a great pity there is an issue with the dealer getting a replacement, especially if they are reputable.
Nitric, I would still take what I am told with a pinch of salt. Though the dealer may be reputable, I have had seemingly reputable dealers lie to me to cover up their own mistakes. I'm not saying this is the case with your situation, but would not jump to conclusions based on one side of the story. The Dealer may have had a specific contract with Niteye which relates to how faulty items are replaced from stock and sent back to Niteye in bulk.
Unfortunately in this day and age, thanks to the internet, we hear a great deal about the few times someone has a problem and not how many people are happy with the service.
It might be worth contacting Niteye directly to explain the situation and that you, as the customer, should be getting good service and the dealer and any future orders they may place has little to do with you and your faulty light. It might help speed up the process. Good luck with getting a speedy replacement, you will enjoy the Eye30 when you have it back.