I have responded to several of your job ads and have not received a response.

We sincerely regret that due to the large amount of resumes received, we are currently unable to respond personally to all applicants.  Despite that, we can assure you that we do review all resumes received and try to respond to the applicants whose background and experience meet the requirements of the open position.  Some applicants are contacted within a short time, based on the requirements of our clients, others categorized to review for future openings.  Most times, resumes are sent to our clients and they select persons that they want to interview.