I had something similar happen to me recently, but not as bad. Someone from across the country "liked" my picture and so did her friend. Then, that friend commented on the picture, "Suzy (or whatever her name was), did you make this?" "Suzy" responded that it was not her cake and that she was just "liking" a great piece of work. So I thought that was great of her to respond that way and that was that. Then, the friend comments again, "You can make this!" I thought about what to do and talked to my husband about it. In the end, I ended up doing what you did and "hid" the comments from MY audience. Those who commented can see it and so can their "friends" but it doesn't show up on my page. I figured since they are nowhere near me, I don't need to take further action.
Some people are just tactless and I hate trying to be the bigger person and wanting to be professional sometimes, but you do what you have to do for your business:/