Tata Motors — unethical behaviour of service centers/no customer satisfaction

I am an owner of 2006 tata safari dicor 3 liter.
My complaint is, tata service centers do not take a trial drive of the car before undertaking any repair work. How would they know how the vehicle feels when in running condition?
Secondly, they take every tata car owners for automotive experts. I say i know how to drive perfectly but am i supposed to know every part of the engine or the suspension? They ask me what's the problem with the car. I could only tell them i didn't like the sound of the engine. Earlier it was smooth, now something's amiss. I could say the car moves like a boat on tidal waters and not at all comfortable on rough stretches. I say, aren't there standards of how a vehicle should sound and move normally? Moreover, if i specify that this part should be replaced, only then they replace it. I ask them to check my horn, so they checked it. But they didn't touch the side-indicator lights problem cos i didn't tell them. Man! I didn't know it had a problem as i didn't know much about it! Haven't come across any tata motors service center which checks comprehensively and makes pro-active recommendations or should we say, prescription for treatment.
Lastly, came across cheating counter managers in your service centers who offered to lessen the bill amount if i pay them extra. I did pay one once. The bill was more than rs 7000 which he changed to 3000 after taking an unofficial payment of rs 2000.
Is this the philosophy of the famous tatas? Should i stop taking pride on myself for owning a safari?
Please help.