Need help with returning devices from a recent order

w8rn8r

About two weeks ago, I had ordered and received three consumer devices from the Zyxel store.

Now, after some testing, it turns out that these devices won't work the way I need them to.

So now I need to return them. However, I had neither received an order confirmation via email nor any help towards returning the devices.

I called the Zyxel sales center in Germany; no help, the guy on the phone says that he can't even look up my order.

So how should I go about this?

Thanks in advance for any helpful hints!!