Byjus - Refund not given even after complaint

I had purchased Byjus The Learning App for my two kids on **/*/**. Receipt no TNL************. Two Sd cards were delivered to me. We changed the school of our kid so we have decided not to go in for Byjus app. Hence I cancelled my subscription within ** days of delivery of the sd cards. Even though the executive Ruchi Dinghra accepted that I have cancelled within time as mentioned by their terms of cancellation. I have not received any refund of the ****/- initial payment. Also, they have deducted one more instalment of ****/-from my bank. Also when I contacted them as to why they are not giving me a refund they told me that we tried contacting you but you did not answer the calls. It's plain impossible that for ** days a person will not pick up calls. Also, there is no need to call as I have emailed them my cancellation. These guys are promised of refund but when you ask for refund they will not give you refund as per their terms.