The worst service I have experienced

The worst service I have experienced. They send the wrong product and I want to deliver the wrong item back so I could get my money back. They can not in accordance with their terms of delivery. They write to me that there are several languages on the DVD and I just need to install the language I need. I tried but still does not work.
I ask once again if I could send it back because it does not work and that they had indeed sent the wrong DVD. The reply was no because now I had had opened it. And that I should be able to install it, since even a 12 year old could figure it out.
I write to them that they do not observe the rules of the EU with the supply and retunering , for this I get the answer that I certainly would not go down the road when it knew several around the world that probably should clear the case.
What I ordered was TeachMe! language course.