Byju's — wrong information and denial to cancel

Address:	Bangalore, Karnataka
Website:	byjus.com

I joined byjus through their invoice byjus[protected] dated 27th oct 2018 and paid 20000/- towards 2 nos 10" tabs provided.
It was a subscription for 2 of my daughters in class xi and iv.
It was promised that the lookin period is 60 days and i can cancel the subscription any time within 60 days. After 32 days i found it is not doing any benefit and wrote for cancelling through mail to the gentleman visited my place. But he replied it is not possible now and asked me to complain customer care. They did not agree and continued the subscription and deducted 2 installments already of 9400 each. But honestly the byju concept not at all useful for my kids.
Kindly help me to cancel my subscription and if possible refund of my installments deducted already.

Regards
Ranjit sahoo
Bhubaneswar
Odisha 751023