Byju's — product cancelation acknowledge not given and receiving frequently messages from bank about emi approaching

I have ordered the byju's product order id[protected]. They given trial period of 15 days.in between they did emi and promised that i[censored] will return the product within 15 days then initial amount will be refund.
We canceled the product with in 15 days and mail sent to byju support team. They asked for the product details. We sent all the details asked by them.
No one came to picked the device after 15 days of cancelation.
Now we received messages from banks thats your emi is approaching please maintain balance.

No one is working for cancelation process.
They have there hidden policies.
There behavior of talking is too rude.

I request if anyone faced the same issue and what action taken by you to solve this issue plz let me know at [protected]