Mango airlines

I booked my flight with Mango airlines last year. Everything was confirmed and paid for. My flight was scheduled for 16h40 on the 2nd of Jan from OR Tambo to CT international. Flight number JE147. So I made all my arrangements according to flight. I checked in online on the morning of my flight only to find out to my shock and horror that my flight has been pushed forward to 15h00. No notification or email was send to me. So I had to rush to the airport to make it in time only to be told our flight has been delayed. Nobody could tell us how long we have to wait. So I started asking people of the same flight if they experienced the same. And they all had the same shock to see the flight has been pushed forward without notification. That is totally unprofessional and unacceptable for that to happen