I used to worry about this. Some call it flaking some call it passive aggressive. Whatever you want to call it it seems that it's pretty much inevitable(for whatever reason)that sooner or later a woman will not get back to you. I've actually had women do it to me who said they would never do it to a guy. Lol. Anyway, this is actually one of my biggest sticking points. Personally, I think the biggest mistake you can make is to call them out on it(at least directly). I personally would handle it by just moving on to the next one and forgetting about her. Sooner or later you will meet a woman who won't do this. Or you can just do it to them. However, I would rather just say to myself "hmmmmm, that's good because this means she won't be wasting my time." Even though it is a rather passive way of her dealing with the situation you can just say to yourself "the right woman wouldn't do something like that" or "I will use it as a learning experience. I guess my game just isn't as tight as it needs to be yet."