ZEN - VX — over charging

I had been there at M/s GL Automobiles,Main Rohtak Road,Bahadurgarh for changing gear oil. they suggested to replace air filter also,and given estimate of 495/ for 2.5 ltrs of Gear oil and Air Filter About Rs 300.00.
when I asked for bill they said youhave to pay VAT on Oil Also. I Just Want To know that

1 That Oil Which they changed was levied extra As VAT shown In Bill ?
2 Rs 198/Ltr was not enclusive of local tax,it's require VAT extra.

Details Of Invoice

Inv No. 185 dated 12/11/2009

Please clarify.

Regards,

M L Goyal