Byju's — Tab not working,no response, refund our money

I had taken 3 years course for my daughter paying Rs.50, 000/- but since august 23 the Byju's app is not working . nor the customer care is replying to the calls email. i want my funds back, we have paid our hard earn money, her 2 years are left only 1 year is complete .please resolve our complaint . i need my funds back .have put several mails they don't reply also.. we are middle class people for us 50k is too much .