Auto AC System Temperature Switch on 2006 Toyota Highlander

I have Auot AC on my 2006 Highlander, the temperature control switch just spins and will not move the temperature. When you remove the knob it looks like an electric reostat type switch, it's held in by two platic clips. Toyota tells me the switch is not replacable, you must replace the whole assembly,$ 850.00. Any ideas in how to fix this?