"Doesn't maintain", "neglects", "falls short of", "doesn't adhere to", "loses track of", "let's slip", "overlooks", "disregards", "fails to uphold", "doesn't fulfill", "doesn't meet", "doesn't live up to", "violates", "breaks", "abandons", "defaults on", "shirks", "omits", "skips over". These are just a few of the many synonyms for the phrase "fails to keep". Each of these words and phrases has a slightly different connotation, so selecting the right one depends on the context of the situation. However, all of these alternatives convey the same basic meaning of someone not fulfilling their obligations or duties.