Naturals Unisex Salon — payment mishandled

Address: Bangalore, Karnataka

I visited naturals unisex and salon, near bda to purchase loreal shampoo bottle worry 635.. But the person handling the billing refused to swipe the card saying ' we don't used card swipe for products you need to purchase only by cash'.. Upon giving the cash again i was refused a bill of purchase saying ' we don't give bills, if you want bills you need to pay 18% gst'

I don't understand this money handling. Why are they afriad to show the record... And why shud i pay anything beyond mrp for products.. Shouldn't it be all included in th 1st place.