Letter of apology

I am writing in order to apologise for my mistake during the last charity event that I personally organised.

The truth is that there was a terrible misunderstanding between some members of my organization. The number of people invited to the fundraising event was higher than I expected, so when I realised that there was not enough time for all the guests to talk, it was too late. Therefore, the scheduling timetabling of the talks was not sufficient to allow all speakers the opportunity to speak (a) wrong.

I am completely aware that I should have checked it all some days before the event, and that is why I must take full responsibility for this unforgivable mistake.

All of us are very grateful that you came to talk to our beloved children, who admire you so much, and we really hope this will not discourage you from attending our next event. I can assure you that, under no circumstances will this happen again. If there is something we can do to compensate you, let us know.
I am looking forward to hearing from you soon.
Yours sincerely,

That was VERY well written.

a= Just a suggestion. What you wrote is fine.