A theory which repeatedly fails to confirm the expected predictions:

probably needs to be developed into a law

probably should be discarded

requires more research time

should be maintained indefinitely,

A theory which repeatedly fails to confirm the expected predictions probably should be discarded. If the given theory is failing once or twice, then the facts and figures can be researched much more to understand the real cause of the error caused. But in case, the theory is again and again fails to confirms the expected predictions, then there is a gap in the facts and figures and the theory being studied and hence it should be discarded.