Byju's — I am complaining about Byju's

I am Aritraa Banerjee, a student of class-6. 2 months back, The employee of Byju's came to my house named Mr.Anubhav Roy and Mr.Swaraj Ghosh. He made my parents sign in some papers and which also consist of some loan papers and made us join in Byju's. Then I received a broken tab. I applied for refund of tab and for cancelling the Byju's contract within 15 days.But they ignored there 15 days refund policy of tab. They also didn't cancel my contract. The apps were also not functioning properly. They didn’t provide us sufficient service as the employee said.
The loan company is threatning us and also the emi was taken.Kindly cancel the contract so that the loan company doesn't threat us anymore.