Aliens Developers — refund delayed

We booked a flat with aliens in august 2019 and in october we cancelled it due to unforeseen reasons. As part of the cancellation agreement we were told that our entire booking amount will be refunded in 4 installments which should be completed by may 2020. Till data we have been paid back only 20% of the booking amount. We have been following up with the concerned cancellation team people but we keep listening from them that the refunds are delayed. We have invested all our savings in this booking and we are now in a financial crisis. Please help. They still owe us 6.5 lakh rupees of our hard earned money.