A greedy madam use the power of voodoo to force young girls into prostitution, till the day when one of them unexpectedly find a way for fight against her.

I like this second attempt better. But dpg is right, If the prostitute who fights against the madam is the lead then the logline should reflect that.

Who is the protagonist? The madam or the prostitute who finds a way to fight back?

If the latter, I suggest reframing the logline around her.