Keef
Transition in the Lille TMA is 4000 feet. Although from your surprise, I am guessing that you have high expectations of what Lille Information is doing for a VFR flight. His primary role is to provide separation between IFR flights, and information relating to VFR traffic such as you are, I suppose.
This means that Lille does not care what QNH or level you say you are within reasonable limits. He just wants to know that you are not in any danger of hitting any IFR flights under his care. If he choses to offer any traffic information to you in the meantime, that is at his discretion. Also it is important to remember that VFR traffic in that area has no requirement to speak to Lille.
It sounds like you did the right thing and took care of your own separation.