Real Dictionary

put upon in British English
to impose on; victimize
to presume on (a person's generosity, good nature, etc); take advantage of
to take unfair advantage of; impose upon
adjective: imposed upon; ill-used
adjective: treated badly, esp by somebody who takes advantage of one's willingness to help them, or by being asked to do an excessive amount of work

put-upon
adjective: If you are put-upon, you are treated badly by someone who takes advantage of your willingness to help them.