This happens to me all the time and it's the most frustrating thing in the world! I used to wear headphones at the range just so people would stop coming up to me and trying to tell me what I was doing wrong. Clearly, I know I am doing something wrong, and that I am not a good golfer, I don't need strangers coming up to me and reminding me of that. I always explain to people that I am taking lessons and this is what my instructor has asked me to do. I appreciate your help but I was given strict orders to not take advice from anyone else. They usually get pissed and storm off but I don't care. I understand that people are just trying to be nice, but it's annoying and really starts to become bothersome after a while.