Why are my dip lights not workin in my renault Clio?

I took my car to a garage and they couldn't find what was wrong with it. My dip lights aren't working but my full beam and fog lights are. The garage changed the bulbs and the switch that turns them on but it didn't make a diffrence. I also noticed when this happened my heating inside my car stopped blowing out air. Has anyone else had this problem and can u tell me what is wrong?