I had this very same bag and it did the very same thing!! nothing much that can be done, I brought mine from MK store and was told that its just the way the leather is made. I ended up selling it because it was annoying to look at. so glad to know that others had this same issue and good luck!!!
Oh my goodness! This sucks! Luckily they said they were fixing it or replacing it. I'm worried it'll happen again though! I love the colour and the bag. It's so strange that my other Hamilton's weren't like this and they're wonderful!