If I make a mistake, I apologise. That's it. It's no more than common decency. I was brought up that way and it's far too late to change, supposing I wanted to change for the worse.
The nature of my apology depends upon the nature of the mistake. I bump into someone, I say "sorry" and think no more of it. If I do something more serious, my apology will be more thoughtful and proportionate.
In a way, an apology is an attempt to wipe out the mistake, or to put it aside, with mutual agreement. If an apology does not achieve the desired result, or forgiveness cannot be obtained, then maybe a further apology will do the trick. There comes a point, however, when refusal to accept an aopology is counterproductive and all apologies are withdrawn. This can result in open hostility - and ruin a relationship if one is involved.
So, apologise, so far as is reasonable, then F^ck them!
TYWD
PS LMAO @ message 28