Byju's — Refund of excess amount paid

I had bought byjus app for 45k for which I had paid initialamountvof 5k and rest 40k I had agreed to pay in 12 EMIof Rs.3333/- but I didnot like that app and applied for cancellation within 15days and that time there executives offered me a discount and informed me to pay only 28k. But as the EMI was fixed for Rs.3333/- they told me that after 9 months of payment they shall refund the excess amount of 1997 to me back ( 3333 * 9 = Rs. 29997/-) .

My 9 months of EMI ended on Feb 2021 but in March also they tried to deduct amount and as I had not kept enough cash in that account the cheque bounced. So from theirfinance team executives called me. I showed the communication I recd from byjus but they were not accepting it. Due to their internal mismanagement their data were not updated and some of their executives were so harsh to me that the verbally abused me and talked in very harsh way. Later on after 15 to 20 days of many mails and calls to different departments and at last when I threatened them to take legal way they stopped calling but I have still not received my refund.

For refund also I have written mails and made many calls to them Once they took my account number and ifsc code and told that they shall refund it that week but I have not yet received any amount I have written mails to them after that also but now they font even reply to my mails.

Their finance team is very poor with no record management and have no general ethics to behave with others. Kindly help me to get my compensation