The technician just cleaned a filter and lied about changing the senor and took 2300 for the sensor and 500 as service charges. All this he said he did in 5 minutes flat while I was sitting in the next room. When I told where the old sensor is, he said it is inside the bag. he even pretended to change it back when I said I don't want such an expensive change. I should have made him do that. Only after he left, I realised that he has only cleaned the fllter and lied about the sensor change. Now, I will not move from the same room if they are called for service.