"Cougar Town" star Christa Miller's manager insists the actress exploited her to get a job on the show ... then refused to pay her $200,000 in commissions -- but she overlooks one teensy detail... Christa's MARRIED to the freaking show creator.

Manager Jill Littman filed the lawsuit in L.A. County Superior Court -- claiming Christa violated an oral agreement to pay her 10% of all "Cougar Town" earnings ... after she helped Christa land the gig ... a sum totaling at least $198,187.

Jill claims Christa paid her for Season One -- but then the checks stopped coming.

Relevant side note -- Christa's married to "Cougar Town" creator Bill Lawrence ... and call it a hunch, but she probably didn't need Jill's help getting the acting job.

Calls to Christa Miller were not returned.

http://www.tmz.com/

http://ll-media.tmz.com/2012/02/21/0221-christa-miller-getty-ex.jpg