Shop In Sai Samaj Mylapore — evading of tax by not issuing bill for the sales made by the shop keeper

Address:

Chennai, Tamil Nadu, 600004

I bought a book sai sat charitra in tamil in the shop put up in the complex of sai samaj, venkatesa agraharam road, mylapore, mas-4 on 18/09/2018 @ 19 hrs. He charges rs.150/- instead of rs.75/- printed on it. No bill is being given. He evades sales and also income tax. Insisted for bill but said no.
The owner is mr rajan. More books are kept for sales.