Mytrip.com complaint: messed up my rescheduling of flight ticket

My flight was (departure dec 30 – return march 1) .On Dec 27 ,3 days before my departure flight i decided to change the flight date .I contacted customer care(myTrip) and they changed my flight date to Feb 6 – march 15 ,i even received an email with new flight ticket and paid $56 at the spot to buy newly changed ticket.On DEC 28 ,one day after i changed my flight date ,i received an email at middle on night (1:30 am),saying $56 dollars which i paid previous day was not enough ,i need to pay some additional dollars to book the newly changed flight and it gave me 1 hour to do so .As i said i received the email at middle of night ,I didnt saw it untill next morning which means the payment link expired then they cancelled my newly changed ticket and now i have lost $1630.41 and I dont have any flight because i was not able to pay the money at middle of night.