Apology Letter For Going Home Early
Dear {Recipient},
I'm sorry I left {event} abruptly on {day of the week}. I should have at least told you I was going home early, but I {wasn't feeling well/had an urgent matter to attend to/etc.} and I had to leave right away.
Which was a shame as I was really starting to enjoy myself. I thought {event} was very well-planned, and I wish I could have stayed longer.
I'd like to make it up to you by buying you {a coffee/lunch/dinner} sometime this week. What time works best for you? Please let me know.
Regards,
{Your Name}