Tvs Motor Company — did not give invoice copy

Hi my name is elayabharathi. Bought my bike apache rtr 160 white from bellandur tvs showroom (Indian motors agencies), bangalore opp to central mall, karnataka on 7/5/2018. During purchase they gave me only receipt and after 30 days they gave me rc. They didt give me any invoice. Later after a year i went to chennai. Now i got noc from karnataka rto to re-register my bike in chennai. They asked bike invoice. When today on 12/12/2019, i called showroom and asked. They are saying for invoice you should ask karnataka rto. Is this fair? We bought the bike. They are not giving any invoice. Even when i initially bought i asked them is there any document pending from your end. They said only receipt and rc. Please someone look at this and help me to get my invoice back.