I understand that frustration of having to spend time and money going back to the dealer with no results.
You have the choice to go to another dealer and take a test drive with the SA to show the sound. TQA has been a dealer that has received several complaints already based on what i've read online so i wouldn't be surprised if they give you the go-around. On the Altis Club site, several complaints to suspension problems were repaired under warranty.
I've been driving with my FC meter on for the last week and have been adjusting my driving style a little more. Based on the FC readings, keeping the car on higher gear always doesn't give me the best mileage returns as compared to keeping the car in a lower gears to get some engine braking and keep the engine in the proper RPM range, so i can go with the least pedal inputs (as in feather light pedal inputs). The MID on the E and G models only show one info at a time unlike the V model MID.