Byju Classes - Refund of Rs

I enrolled my child with Byju online course for * year during ****-** with Rs.*****/- * year EMI, and contunued with * year having several complain for Tab is not working. That was still not resolved having paid for. Due to time constraint of child he needs to close the programme. From Jan'** we have made several mail to Byju for cancellation of programme and stop deducting futute EMI. But every time they denied and said once enrolled could not be stopped.For which they are deducting EMI from my card. And also one more thing the donot cancell the programme simultaneousely donot send the book for next classes as the child was admitted in the * year course from *-**.