It does matter which side they are on. The foglight on a RHD car is on the right, and on a LHD car it's on the left. Whoever you bought the lights off of have a word with them and see if they've got a duff batch, as I had a set of what were supposed to be Rh but the beam pattern was for LH.
If your a competent lecky, have a go at just linking the wires from side to side, but I'm not sure how this will stand on the MOT.