misuse
Stopping overutilization or misutilization of health-care services would lead to savings.
Many of the school buildings were used for non-teaching purposes, including teacher accommodation; other cases of gross misutilisation included prolonged use as a storage space.

SMART Vocabulary: related words and phrases

Using and misusing
adopt
adoption
avail
avail yourself of something
be/go heavy on somethingidiom
exhaust
give/allow something full playidiom
go into something
go through
gobble something up
make capital out of somethingidiom
spare
spent
swallow
tap
turn to someone/something
turn/use something to good accountidiom
unblock
underuse
underused