DJ Khaled was slapped with a lawsuit by a NY jeweler who says the rapper ordered a ton of bling, but refused to pay for a thing -- and is now more than $100,000 in the red.

According to legal docs obtained by TMZ ... Khaled got 2 Rolex watches, a custom made diamond chain, a pair of diamond earrings, and a 4 carat diamond ring from Rafaello & Company in 2012.

R&C says it had a written agreement with Khaled that gave him 15 days to check out any jewelry the company sent him. The deal was ... if he liked the goods, he would pay -- and if not, send 'em back.

But in the lawsuit, R&C says Khaled did neither -- keeping the watches, chain, earrings and ring ... and never paid a dime for them when he was billed. 

We reached out to Khaled's rep, and so far no word back -- but as his biggest hit says ... "Got money on my mind, I can't never get enough."