I dont know how to get him away?

Ok, I dated one guy and lets call him Joe. Well we dated for a month. We broke up and 2 months later i meet my bf now Bob. I love Bob so much. And my ex Joe started talking to me and i thought it would be short and sweet like "hi, hows life. gtg. bye" oh i was so WRONG. Joe keeps txting me and its getting real anoying. I even had Bob tell him to f*** off. But that just made things worse...i need to get joe to go away. any suggestions?