I've used to protect my kitchen top, a german product, Lithofin
Stainstop (what a smell!!! really nasty)but he has left a film on top.
How can I remove it?? I phoned in the main office in Germany and they
don't have a clue... they told me that I had 20 minutes to remove it,
after that it's impossible to remove it...

Certainly, the instructions are very clear about not allowing it to dry out
and to mop up any excess. What does the result look like?

Christian.