If supernatural is anything to go by, "deals with the devil" are hardly ever actually made by the devil, but rather by his army of darkness. Luci is either locked up or has bigger fish to fry, like starting the apocalypse.
Head to your local crossroads at night consecutively until you meet someone there. It could be a demon working for the fallen one, or it may even be Papa Legba (who's sometimes equated to the devil by those unfamiliar with hoodoo) the Iwa/Loa of the crossroads
More than likely, though, you'll just be standing there alone in the dark
But know if you do encounter someone and make a deal, you'll have to pay up your end when they decide you must
It doesn't matter if you agree upon a time when you'll pay, once you give them your soul, they have control