Besides Buck268's methods...just tell them that you will ruin their rep if they dont pay u back or get you the shrooms. A dealer only has money on his mind so this will fuck with him if you act serious when telling him. I fhe thinks your kiddning then tell everyone that buys from him that hes been ripping everyone off or that hes not safe to buy from. I almost had to get into that the other day with some jerkoff (only cause i can't fight).