The seat belt extension, is not allowed!

I got myself this seat belt extension for our Focus in conjunction with a child seat Cybex.
As some others have noted before me this seat belt extension is not allowed.
When asked told me that the Federal Motor Vehicle Office with these seat belt extension in Holland is not under the specified test number. So it's a fake and it is not allowed.
Here is the email of KBAs:

"Hello Mr. Cicchella,

after the initial feedback from the original Holland were we sent to approvals which clearly demonstrate that a seat belt extension, are not covered by the aforementioned approvals.
Thus, these are a misuse of the approval mark, so a fake.

The Dutch authorities will approach the actual license holder and refer him to the abuse.
On the part of the KBA will be shortly an indication to Gurtverlängerungen on the KBA website.
Take legal action to prevent the distributing of such products are tested in parallel.

Thanks again for your reference and continued safe and enjoyable journey.

Yours sincerely

XXX

Kraftfahrt-Bundesamt
Department Automotive Engineering

24932 Flensburg "

I hope I could bring a little clarity in the matter.

Greeting Michael