A California man has filed a civil lawsuit against a Las Vegas casino for not stopping him while he lost $500,000 while gambling drunk during a February trip. "Just picture a drunk walking the street and he's drunk, and someone pickpockets and takes his money from him. That's how I characterize it," Mark A. Johnston told CNN on Thursday. "I feel like it's the days of old Vegas, the way they've been extorting me with letters and attorneys." Johnson, a Ventura resident, said in his civil suit that he was visibly drunk before he and a friend walked into the Downtown Grand Las Vegas Hotel & Casino over Super Bowl weekend. His suit claims he has no recollection of the 44-hour period he spent at the casino, including a 17-hour gambling binge. "Mr. Johnston, an experienced gambler, was dropping chips on the floor, confusing chip colors, and slurring his speech badly, and he was unable to read his cards or set his hands properly," the lawsuit stated. Johnson allegedly opened four lines of credit with the casino — two worth $100,000, one worth $50,000 and one worth $250,000 during the weekend. A spokesperson for the Grand Las Vegas declined to comment on the lawsuit. But CNN reported that the casino is under investigation by the state gaming control board for possible violations including "permitting persons who are visibly intoxicated to participate in gaming activity" and "complimentary service of intoxicating beverages in the casino area to persons who are visibly intoxicated. Johnson's lawsuit also accuses the Grand Las Vegas of later contacting the Hard Rock Hotel and Casino and discouraging staff there from doing business with them. Johnson, a retired car dealership owner and frequent traveler to the city, told CNN that the suit is less about the money and more about being taken advantage of by the Grand Las Vegas. "I am not a sore loser. I've lost half a million. I've lost 800,000. I've lost a lot of money," he was quoted as saying. "This has nothing to do with that. Obviously I can afford what I lost."