Recruitment agencies

Yesterday I got an email on the Linkedin networking site from a recruitment consultant asking me to add her as a connection and to contact her to discuss possible vacancies.  I emailed her back to say that I would ring her later that day which I did and she promptly informed me that she would return my call later which never materialised.  This seems to be a common occurence with recruitment consultants - not having calls returned.. what hope do people have in finding employment if they don't get the support that they need from those whose job it is to do just that?