Bake that cake OP.
Go back next saturday at the same sort of time, armed with cake. Big ole grin plastered on and pull up a chair, sit down, introduce yourself and offer cake around.
Faced with unwavering friendliness and cake, the average brit will find it impossible to be rude or unpleasant. They will take the cake (the bait!) and then be stuck, you can't fight friendly.. or cake... You can commiserate with Babs, its SUCH a shame that Sally Seller screwed her over, how terrible... and come up smelling of roses (and cake).