*Oh dang, Tisha Campbell Martin and her hubby Duane are being sued by their mortgage company, City National, over a seriously past due house note. Um, they owe something around $430K.

TMZ says Duane took out a $625K home equity loan in 2008 on a waterfront property in Lake Arrowhead, Calif.

But it wasn’t a smart move ’cause they were still in debt at least $730,000 on their mortgage. It was totally irresponsible because they defaulted on both loans and suffered a foreclosure on the home, which sold at an auction for $925k.

But the couple is outraged by the lawsuit, saying the bank is preying upon them and discriminating.

According to their rep, the bank received a $400 million government subsidy in 2009 to help families like the Martins through the mortgage crisis.

In fact, Tisha and Duane believe they don’t have to pay a dime. They will be taking legal action against the bank.