I receive a lot of calls like yours everyday too, and I make similar calls everyday so I understand your frustration.
Typically I take calls from people who are trusted sources. A trusted source is typically someone who was referred to me, or someone I became familiar with because of information they have provided me that I found to be valuable.
Some steps to take:
Use Linkedin to expand your network of people that can refer/introduce you to the targeted audience.
Build out your personal brand by providing valuable insights on how to help people reach their business objectives.
A starting point for the above can be by just following and responding to Linkedin questions; leverage the content to build out a blog, and then in your calls alert people not only to your company, but to your blog, and they will begin to understand how you will support them in achieving their business objectives. Linkedin is one of many different mediums that you can use to build your personal brand.
In today’s world it has become just as important for a sales person to perform integrated selling, just like a marketer needs to perform integrated marketing. (Using all mediums available)