Are you doing what you said you would do for your clients? If the answer is yes, this could be the reason you aren't getting more referrals. Simply put, it's quite possible that you're not getting the referrals you deserve because you are doing exactly what you said you would do. Confused?
There is absolutely nothing wrong with doing what you promised, but it's just not unique or exciting. You are simply following through with what your clients expect from you. And that alone won't inspire your clients to tell everyone they know about you and your company.
Your clients will talk about you when there is something unexpected to say, something that causes you to stand out from the competition. They will talk about you when you do something surprising—in a good way. Doing exactly what you said you would do—and nothing more—makes you a good person and good businessperson, but the honest truth is that it isn't very exciting. To get your clients to share you with their world, you need to do or say something surprising, unexpected. Something that makes them say "Wow!"