Ex-Idol Finalist -- I'm STRUGGLING to Get Paid

Unless you're Carrie Underwood, life after "American Idol" can be a bitch ... especially for singers like Kimberly Locke - who claims she got robbed by some around concert promoter bastard for years.

According to Locke, she had to fight tooth and nail to get paid to perform in a 2008 "American Stars in Concert" tour - featuring several alums AI - even after a court ordered the producer Scott Stander Hand over the dough.

Locke - who finished third in Idol 2002 - AI now says, "I worked very hard on this tour, and I was disappointed that Stander failed to pay me it was not only unprofessional, but very insulting and totally unacceptable"