Auris heater issues

[AndyClockwise]

I'm looking for help on an issue with the heating on my 2007 Auris.

This morning the left hand dial which controls whether air is directed to face or feet or windscreen suddenly became very stiff.

I managed to turn it to another position but seem to have now broken it as it spins freely and the air is still directed towards my face.

Is this likely to be an issue with the dial and mechanism or is there another control unit that needs replacement?

Thanks in advance