Just go to any pin and do as he/she says. just write a comment with their username and the @Symbol and hopefully you will get added after they look at your profile. I know what you mean though, sometimes they dont appear. I find that this happens usually when it's a common name. If there are a ton of users it will only show up so many. You could try and follow some of the links on their profile and see if you can find other contact info for them to make the request. What part is not working for you? Although I may have logged in and seen a question that does not mean I always have time to answer it right away. Not that I need to answer it in 24 hours but it had not even been that yet. I will endeavor to answer all the questions I can but it will at least be when I can and I may also wait for a few comments to build up so that it does not take all of my time answering questions whenever they come in.