Granted Avram Avinu didn't accept the initial sentence, but that was regarding a decree of Hashem.
Nowadays, is there in the legal structure an appellate Beis Bin where one can have recourse to have a decision reconsidered?
Historically, are there any examples in Sha"s in that regard?
Also, this is probably going too far, but is there anything like that for a Teshuva? That I would doubt.