"Get one due" can be synonymous with several other phrases, including "receive one's rightful reward," "earn what one deserves," or "get what is owed." All of these phrases suggest that a person has done something worthy of recognition or compensation and that they are now receiving it. Other synonyms could include "receive one's just deserts," "comeuppance," or "get one's fair share." Essentially, any phrase that implies a sense of justice or fairness could be used in place of "get one due." Regardless of the phrasing, the general sentiment is one of satisfaction with the outcome and a recognition of one's efforts or accomplishments.