The phrase "got one due" typically implies an impending obligation or responsibility that needs to be fulfilled. However, this phrase can be rephrased using various synonyms depending on the context. For instance, you might say "a task is pending," "an obligation is looming," "a duty is waiting to be fulfilled," "an assignment is due," or "a job is awaiting attention," among other phrases. Other potential synonyms might include "an outstanding commitment," "an impending responsibility," or simply "an upcoming deadline." Whatever phrase you choose, the important thing is to ensure that your message conveys the sense of responsibility and urgency conveyed by "got one due".