Hi guys, I had this issue with mine, the buttons for the heated seats, TRC, headlight level, headlight washers and rear fog had all blown.
These are grain of wheat bulbs, I ordered 50 from ebay from china for £7, ok these take couple weeks to get here to the UK but much cheaper than going to auto accessory shop.
The grain of wheat bulbs un-twist from the bulb holder itself and then you can pull the bulb out, slide new bulb in and re-twist the wire in place, sorted.
I done all my bulbs for £7, when auto accessory shop was charging £1.50 a bulb. OK I havent done the heater controls as these wasn't blown but I've already opened it up and they are the same type of bulb, so the same principle applys.