Byjus learning app - Refund Not Provided

We have ordered a course from byjus, we have initially paid ****rs for it, and the rest of the amount was due to pay on cash on delivery, but after some time due to personal issues we understand that we would not be having that amount of money which is required to be pay at the time of delivery, hence we have cancelled the order but they have not ye lt refunded our **** rs downpayment amount, we wrote so many emails also called their pathetic customer support but they are not responding, every time they asked us to wait for ** minutes and they will call back for a refund, but from the last ** days nobody has ever reached us for refund, their customer care and internal management is so poor and pathetic that they even didn't know how to talk to a customer