to offer an apology;  to make one's apologies/excuses;  to apologize;  to beg somebody's pardon
Apologize to your neighbour!;  Say (you're) sorry to your neighbour!
It wouldn't actually hurt to say thank you/sorry, would it?
I'm not satisfied with an apology!
(I am) sorry;  excuse me;  pardon;  I beg your pardon
So we have two, sorry, three options