Toni Braxton — Sued Over $57,000 TV Poster SNAFU:

Toni Braxton is responsible for over $57,000 in STOLEN ADVERTISING for her TV show “Braxton Family Values” — so says a new lawsuit … and now, the singer’s being sued BIG TIME.

A company called National Promotions & Advertising filed the lawsuit in L.A. County Superior Court, claiming it entered into an agreement last year with the producers of Braxton’s WEtv reality show — including Braxton herself — to promote the show’s 2nd Season.

According to the lawsuit, NPA agreed to post 4,300 “BFV” posters around the country in exchange for a fat paycheck — $57,322.29.

NPA claims it completed its end of the bargain in November — days before the premiere of the show’s second season — but Braxton and her producing partners didn’t pony up.

NPA says it’s been trying to get paid ever since … in vain … and now, it’s suing for its money … plus damages.

A rep for Toni tells us the singer is not involved in marketing budgets or payables for the series, and says such decisions are handled by WEtv.