What is the ruling on paying off debt to Al-Rajhi Bank through Bank AlJazira without interest, knowing that the employee stated the permissibility of this based on a fatwa from the bank's Sharia Supervisory Board?

If the bank has a reliable Sharia supervisory board and it has issued a fatwa that the transaction by which the debt was purchased is permissible, then there is no objection to following it in that, provided that the transaction was executed according to the controls set by this committee.