Heater control panel light W202

[everythingpure]

I am on about the facia lights that are in behind the two dials for controlling the heater. The dial on the left is fine, but the right one doesn't light up. It's not the bulb, as I have swapped them over and have the same problem. Any ideas what else i can try?
if I have to replace the unit, how much should I expect to pay?

thanks
Mikey