Byju's — cancellation and refund

I had purchased the products on 4th december 2018 and received the 9th standard course on 20th december 2018 till date mentor and byjus team member had not contacted with us. Then i send email 📧 to byjus for cancellation and refund the amount on 27th december 2018 many times later next day one person megha told us refund is not possible because 15 days is over. Now i don't want above products but nobody is responding they knowingly extending the date and sanctions the loan before 15 days trial due to all this i am suffering from mental trauma. Please cancel application immediately.