Boarding Gates

I am so disappointed with Mango as on 19 Jan 2020 my fight was booked for Bording 7:25 flight time 7:55 I came at the boarding gate 7:39 they did not let me through only telling me the flight is gone. Boarding gates closes 15 min before departure this means I was still on time. Leaving me just sitting there telling me I can just go and purchase a new ticket. So no exceptions nothing it was at 7:43 i told them the flight is only leaving at 7:55 the only response is the flight is gone. I dont have the capital to go and invest in flight tickets as desired. Yet to top it all when I got at the boarding gate the service attendant didn't even bother to check my ticket, just said the flight is gone. So nothing can come of this this humanity we are dealing with.