Even if, as a skilful means,
one does not accept another’s apology,
so as to further awaken that person,
one should not bear any grudge,
so as to further awaken that person.
– Stonepeace | Get Books
The nineteenth secondary transgression is not accepting others’ apologies. The object is someone who, for example, had been angry with us and then, realizes that it was wrong and apologizes. If we refuse to accept the apologies of the other person out of anger, vengefulness, spite and so on, we make a transgression with afflictive emotion(s).
If there are no feelings of anger or hatred, but we still refuse to accept the apologies because, for instance, we do not feel like accepting, we then make a transgression without afflictive emotions. [Even wrathful manifestations of Bodhisattvas have no genuine anger; only compassion.] The exceptions are…
 If it is better for the spiritual development of the other person that we do not accept his apologies at this time, we do not make any transgressions.  When the apologies have not been offered in the correct ways, we do not need to accept the apologies.  When we have reasons to think that the person is not serious in his apologies, we do not need to accept the apologies.
The Bodhisattva Vow
Lama Dagpo Rinpoche Jampa Gyatso