Maruti Service Masters — Estimated cost of repair

Address:

Chennai, Tamil Nadu, 600042

Gave my car which was half wheel under water. I was afraid to start it. So just towed it to MSM guindy. After 1 month they say the service charges will be 90000. Replacing almost all parts of car. When water did not raise above half of wheels and no water got inside, how can the damage be so much? When every other car which is fully drowned in water costs just about 20-30k to get repaired how do we believe this. It is daylight looting. Now when I say Im taking the car back they say parking fees of 3500rupees.
Please help me with this.