Problem is that the MA trigger works only "one way". It's triggered only when value of score increased. Basically the trigger fires only when:
OLD_SCORE < TRIGGER_VALUE < NEW_SCORE
You have imo two options:
1) Create new trigger type (this might be a bit tricky)
2) Create scheduled task that decreases statuses for all contacts at once. (for example every midnight or more often if needed)
The second option has one positive sideefect -> better performance.