Shame they didn’t remember that in Paris in 1919.
One could take Paris in 1919 as an example to make things worse for France:
-first, one must link the Congress and the fate of France, thus no final treaty is made as IBlameCommunism stated, but the initial treaty is linked to the general thing, as in 1919.
-second, the victors must suffer more, as in WWI. A British defeat at Waterloo might do the trick, as could some serious naval defeat of the British with a subsequent fear of invasion.
-third, I'd propose to hold the congress in Berlin or Amsterdam, where the local government and population may be more anti-French, as France and Paris were anti-German.
-fourth, kill Talleyrand. He was an extremely skillful diplomat. Without him, France is in a significantly worse position. I doubt if in 1815 you could deny the French negotiations altogether as in 1919 happened to the Germans, but if the peace terms are negotiated, Talleyrand makes a difference.