Unfortunately defective after less than three months

The device is actually quite great. At the design and the functions there is absolutely nothing to complain (adjustability, comfort, rear light, etc.) There are also no problems with the battery cover or other mechanical problems.
Unfortunately, the light suddenly goes not to (it is not by accident the transport lock .....).
Control or LED is defective?
However, I know of no alternative, because I need a lamp with battery, but no frills. So once again re-appointed ...

Does anyone know of any other lamps of the same style in a similar price range?

One more thing:
The support of two brothers is via e-mail ( [email protected] ) Can not be reached (error message from the Postfix mail server).
Let's see if someone on my email (21.2 in 2014.) (Via the support form -> website) responds.
Addition:
On 02.25.2014, the two brothers support reported by e-mail:
"... Thank you for your e-mail, please send the goods to your seller, this assumes as part of the 2-year dealer warranty to exchange / repair."
The answer, however, is wrong, because Amazon does not take over the repair, but only the return and refund the purchase price.