C3 Presents, the production company behind Lollapalooza and Austin City Limits, has refused to pay a pair of Brooklyn graffiti artists it commissioned for a pop-up “Metallica Museum” because, C3 claims, the street artists’ crew was “obscenely drunk” at the event, threw a sex toy into the crowd and brought druggie Vice blogger Cat Marnell along for the ride. The artists, called Mint & Serf — who have created work for Ogilvy & Mather, Marc Jacobs, Orbit gum, the Ace Hotel, Nike and Red Bull — say C3’s security used “deadly force” by pulling knives on them “with the intent to instill fear of injury” if Mint & Serf refused to leave, noting the knives were drawn “ostensibly to remove the wristband.” The Metallica attraction was part of the Orion Music + More festival in Atlantic City in June, and C3 hired Mint & Serf to create a mural inspired by the heavy metal band. But in an e-mail obtained by Page Six, C3 also says Marnell “apparently started an altercation with several fans.” The graffiti crew is further accused of spraying Metallica fans with paint. Marnell admits, “I sprayed one person, I apologized. He said it was cool. I didn’t do it in any way to hurt him.” But Mint & Serf countered in a letter from lawyer Joseph Santoli that “the drunken crowd” at the event “was not controlled properly,” and that they were unfairly thrown out after their work was “accepted by C3.” C3 did not return requests for comment.