i think you can send it back and get you money back (including shipping costs) - just send it back and tell them they should refund you (no change, no repair, if you are in 14 day from delivery time).

May be that needs some time, but thats the way in germany... If they don't, you need a lawyer, then they will do.

btw, you have to send it back in any case (for proof and possible repair), so in this situation you loose nothing by sending it back. Just do it in a way, that you can proof that you have send it...