HONDA 2 WHEELARS INDIA - Motor vehicle grievance

Hi, I tried to purchase a new motorcycle from Honda showroom, on the day of delivery after starting the bike black smoke came out from the engine & silencer pipe. After a day they have fixed it and then i requested them to give something in writing saying if any further issue happens they should replace the bike with a new one and not just fix it. They are saying they are the Honda dealers so the free *yrs honda warranty is enough and they would not provide any sort of guarantee in writing and since the registration has already been done i am bound to take that same bike and also asked me to try the consumerhelpline.gov.in regarding the issue. Even after lodging the complaint they called me back and said the same thing. (Grievance docket number: *******)
Please help me in this regard, i have not even taken that motorcycle out of the showroom yet. I just have the delivery documents with me as the incident happened during the delivery day. Even after wait of a week or two am getting the same response from their side. Moreover the first servicing period got over after *weeks of the delivery date which seems fishy too. Right now i lost faith with those showroom guys and want the full refund, and try to buy bike from elsewhere. Its like i have done a crime paying for the bike upfront.