This is a common objection you will hear and the best way to reply to it to win more recruitment business is via this email template below.
Hello [NAME]
Thank you for clarifying, I thought as much but I wanted to reach out to you regardless. Is there ever time where you would require a 3rd parties agency to assist with the candidate pool?
If it would be a good use of your time, if it is a cost or service based issued I would be happy to put together a proposal to send to yourself that would suit your business needs.
Kadz