Byjus app - Refund for the course

On ** th June ****, I purchased the Byju live class for my son for class * by paying them rs ***** (one time payment) with the promise of *% cashback which I didn't receive yet.
After paying the full fees my son was not assigned the fresh batch but was put in the running batch whose syllabus was half completed. (This glitch occurred even after I had confirmed *** times that he will be put in a fresh batch before buying the course).
To resolve this problem I had contacted the helpline team of Byju many times. But still the problem remained unsolved. So finally I placed the request for cancellation and refund for the same. But I did not receive any call from Byjus. It means that no action is initiated at their end towards my request for cancellation. After that I made number of telephonic calls to their helpline numbers and menters till the date. Every time the answer received is that the request is forwarded to senior manager and he will contact you. But till date I have neither received the refund nor the call .it's my humble request to help me get my hard earned money back.