Hello, as there aren't any real life examples of never-ending transfer bans, it's not something we'd look to implement.
One possible solution to the problem would be for you to edit the rules of a league, and select Financial Fair Play Rules under Fixture Rules of the nation, then perhaps set it so that if a team spends a certain amount of money on transfers/wages, they will receive a transfer embargo. We believe that's the best way to go.