Gupta Brothers - GST Evasion Avoidance

Dear Sir/Madam,                           I wish to bring to your notice and report  the continued and  rampant GST evasion and avoidance  by the following business entities :
SAURASHTRA NIMKI HOUSE*** SARAT BOSE ROAD, NEAR SARAT BOSE ROAD POLAKE MARKET, KALIGHAT, KOLKATA- ******
NEW SAURASHTRA NIMKI HOUSE*** SARAT BOSE ROADNEAR SARAT BOSE ROAD PO, SOUTHERN AVENUEKOLKATA
NEW SAURASHTRA NIMKI HOUSE  
SHOP NO. * ,  */* , SAMBHUNATH PANDIT STREETBHOWANIPORE, KOLKATA- ******
These shops are in the business of selling readymade edible stuff and snacks and do brisk business all through the day, right from morning  worth lacs of Rupees everyday. These shops are owned  and run by one Sh. Jaykar Nimavat. However, these shops accept only cash payment against the sale  and issue no receipt or bill or cash memo of any kind against the sale. The shops also do not accept any online or digital modes of payment. In fact there is just no practice of issuing any bills/receipts/cash-memo/invoice against the sale thereby leading to rampant evasion and avoidance of GST, resulting in loss to State Exchequer.
Further, a  similar unfair trade practice is also observed by M/s GUPTA BROTHERS having outlets in Ballygunge , Bara Bazar, Shakespeare Sarani, Salt Lake, Elgin Road, Camac Street, Bhawanipore, Alipore and New Alipore. The smaller outlets of this Group like that in Elgin Road and others only make cash sales and do not ever  issue any receipts/cash-memo against the sale.
I am sure you can appreciate the extent of GST avoidance and evasion by these businesses with such a modus operandi. If properly investigated many more violations and evasions can be detected against these businesses including income tax evasion too.
I hope this complaint is investigated and corrective action is taken so as to plug the loss caused to the Government by these unscrupulous elements.