It is possible to want an apology mainly because it would certify your version of the past.

Sometimes what you want from an apology is not the remorse but the ruling. An apology would establish, on the record, that you were not imagining it and not being unreasonable, and that certification is what the wanting is really about. Which is why apologies that arrive without acknowledgment of the facts feel so unsatisfying.

If you are waiting for one, ask what specifically you need it to confirm. Sometimes you can get that confirmation elsewhere, from someone who was there or from your own written record. Freeing the confirmation from the apology means you are not waiting on a person who may never offer one.