Our Manual Control Heater Keeps Coming Back On After It Is Turned Off.

We have a manual heat/AC system in our 2012 Santa Fe. Even after we turn the system off, as explained in the owner's manual, it intermittantly turns itself back on. The fan also will occasionally "surge" on. Driving over bumps seems to increase the frequency of either of these problems, but not on a consistent basis. The dealer said that this was normal because of the sensors on the dash board, but if we are reading the owner's manual correctly, those sensors are only for vehicles with the automatic climate control system. We strongly suspect the dealer does not have a clear understanding of our problem, or is simply giving us the run around. Help!