Prepinsta - Prepinsta Denying Refund

I bought PrepInsta Prime's * month subscription. But all the material that they advertised was not present and the customer service was extremely rude and unhelpful. So, I applied for a cancellation of my membership * days after I purchased it to get a refund as per their ** days money back guarantee* policy. I called them and they talked rudely to me and each time told me to wait for a call next day. But the call never arrived. I mailed them and there also they lied and said that I'll get a call but that call also never arrived. They are simply delaying the process so that they don't have to give me a refund. I bought the subscription based on their false advertisement and now they are not even honouring their money back policy. I feel completely violated