how to find info about a past flight

Hi, We came back from Geneva on 28th Dec a day late on Mon6993. I have contacted the airline Monarch to complain re the 25 hour delay and they said it was due to weather end of story. We know the reason was due to the ground crew at Geneva not being able to load the luggage on the plane. We were on it and our luggage was on the tarmac for hours the pilot went out to remonstrate and when it was finally loaded and a new flight slot gained the pilot had run out of flying hours. therefore we had to stay over night in Geneva. The flight was changed a few days in advance to a titan plan, 767 I think, and the ground crew could not load it properly hence the delay. I have looked up the flight number on here and for the 27th and 28th the flight does not exist.
I raised the issue with the CAA and they are not interested as the airport was Switzerland. I have written to Titan for info on what happened with the flight but they will not disclose anything.
Can anybody point me how to find out information with regard to the flight, any help appreciated