Is the apology of one who insulted the companions of the Messenger of Allah, peace and blessings be upon him, acceptable, especially if the insult continued for months?

Slandering the Companions is one of the gravest sins, and whoever disparages any of them, know that he is a heretic. This is because they conveyed the religion to us, and impugning them is impugning the religion. The ruler must punish anyone who slanders the Companions with a punishment that serves as a deterrent to others, and pardon is not permissible for him. As for one who repents, Allah will accept his repentance, and his repentance is to declare his disavowal of what he wrote and to explain the virtue and status of the Companions. Allah Almighty says: (Except for those who repent and correct themselves and make clear [what they concealed] - those, I will accept their repentance; and I am the Accepter of Repentance, the Merciful.)