Byju's — not accepting cancellation of agreement even I am unsatisfied

Address:

490021

Byju's counsellor had booked a session with us for my brother. He convinced us to buy the product for 6th to 4th class. He asked us to pay 80, 000 which includes 12000 rs down-payment and the rest of the amount would be taken as loan. I paid the down payment and my aadhar card and pan card details were taken.
My loan amount was disbursed on a/c even before i got the product. Now, i called them back to cancel the product as my children aren't really satisfied with it and nor us but was not able to reach them for a long time. Finally when got in contact with them, they are refusing to take it back and i'll have to pay ₹6500 emi amount for nothing. They failled in half yearly exam only due to addiction of tablet. I inform them also this condition but they were not ready to listen any problem. I use to go for my job about to 60 km from home and come back late. So no time to teach them with help of mentor.

I just want them to take back their product which was barely used and cancel the course and loan also.