I mean this in an honest manner and not an attack, what do you feel they need to apologize for? What statement or promise did they make that they didn't follow through on and didn't explain why?

If it's just a situation where you didn't like what was presented and you felt they should make certain changes that they never said would be made, then that's not anything they would need to apologize for.

If they didn't follow through on something they said, then we can review that and decide if there's something to apologize for there.