Transfer audience from one automated mailchimp list to another

I need a mailchimp expert who knows how to link one automated email campaign to another. My audience receives emails from an automated mailing list, totalling 100 emails, the maximum I'm allowed. I want my audience to automatically go onto the next automated mailing list, for another 100 emails, but I can't work out how to do this. As a result some of my audience have stopped receiving emails, so I need them added back onto the new automated email campaign. Can you help?