Byjus - Byjus app is taking money by processing emi without consent for a cancelled product

Byjus app is taking money by processing EMI without consent for a cancelled product. This product is not useful and they hesitate to cancel once it is given as a trial demo. Already given request for my EMI cancellation still they are not ready to cancel the EMI and taking money from account unnecessarily. This is a fraud practise they usually do to take money from customers.
They have taken a total amount of Rs.*****/- from the account. They are taking the blank cheque and without consent. They process EMI and taking money from the account.
They have very worst customer service and never hear the pain of the customer. Even they don't give any support to children once they sell the product at home. If the product is not feasible for children they won't take the packet back and will rob the money from customers.