^^^ they do adjust. and are £12 something from renault. not expensive but i would try adjusting it first. if it needs replacing, make note of the colour of the terminal block, mine was white which is the common one but there are 4 or more colours apparently.
first remove the switch by twisting it (anti-clockwise iirc). then pull on the pin that rests against the pedal until its fully out, you pull fairly hard but not really hard. then push the pin all the way in. pull the pin out carefully one click, twist it back in place on the pedal, try the brake to see if it lights up correctly. if not pull the pin out another click etc. keep trying and you will get it right.