I bought Swift Zxi from competent automobiles shivaji marg on Feb 2010 DL 2CAL 2661, after driving around 6000 to 6500km i decided to put a CNG kit on my Car , Competent Service guys told me that if you will fit CNG kit from us then the warranty of the car would not affected otherwise your cars warranty will be not valid, so i decided for the fitment of CNG from Competent automobiles and they charged me Rs.36000 for the fitment and they said if you want to endorse in your RC then you have to pay Rs. 4000 extra. so i decided just to pay Rs. 36000 for fitment and the other formalities i will take care of it , and Competent people prepared and gave me the file required for submitting in the transport authority for the endorsement of CNG kit on my RC. When i went to the transport authority to submit the file the official told me that "THE KIT THAT HAS BEEN FITTED ON YOUR CAR IS APPROVED FOR BS-III CAR AND AS YOUR CAR IS BS-IV THIS KIT IS NOT APPROVED ON YOUR CAR" which was not informed by any official of competent service center in shivaji marg to me, so i went to the service center and had word with the works manger Mr. Menon and he replied in a sarcastic way that " YOU TOLD US TO FIT A CNG KIT AND WE DID IT AND NOW AS YOU HAD NOT PAID Rs. 4000 FOR ENDORSING SO WE CANT HELP IT OUT" and after fitting this kit the performance of my car has being ruined very badly . every week regularly i m visiting these guys and till now no solutions had been provided to me. I had registered a complain in Competent Head Office as well as in Maruthi( Complain no: 3645798093 and 7169748962). but till now no resolution has been provided to me and i am into this frustration from the last 2 months.