Aertrip - Booked tickets through the Aertrip travel agent No notification that the airline was not operational

I was looking to travel to Vietnam on a vacation with my family (senior citizens and infant included). I worked with the Aerptrip travel agents to book flight tickets for my entire family originating from Bangalore on Vietjet Air. The flight was to take off at **:** PM. ** hours before the flight I tried to check-in online but there was a message on the website that for international flights, passengers have to visit the airport to check-in. I then contacted the Aertrip travel agent who had helped with the ticket booking to help me check in online but there was no response from them. When I landed at the airport, I was told that there is no such flight operating out of Bangalore. I would have expected the Aertrip team to do due diligence before booking passengers on an aircraft which is not operational. Atleast they should have informed me that the flight was not operational but there was zero communication. In addition, to the pain of planning (which took more than two months) and expectation, it was the situation that they put me in (midnight at the airport with elderly parents and an infant) that made me file this complaint. This should not happen to any other customer.