In Siddipet, a small town about 100 kilometres from Hyderabad in Telangana, Yellaiah is worried as his son was sent back from school. "The madam at school did not accept the 500-rupee notes I sent to pay fees and sent him back," he said. Most private schools here take fees by cash and not cheque. Yellaiah says his son will end up missing his exams this week if he does not arrange for the money.