Contact stopped responding

Hey guys,

So I cold emailed an investment manager at a smaller PE fund and he was kind enough to have a coffee chat with me. He basically informed me that they already had an intern, but that I should "lock up" the next intern slot that became avaliable. I had a coffee chat "interview" with his associate which went well, and he told me that he needed to confirm dates with the manager.

The issue is that the associate was out of office immediately after our interview, and I never heard back from the manager. I contacted the associate when he returned to the office, but the manager was on leave. Finally when the manager returned, he informed me that they already had an intern (I assume he forgot about our meeting since it was a month earlier, I probably should have clarified that I was talking about the next internship slot) but offered me another internship at one of the companies he was on the board of. I politely declined, and clarified that we talked about internships for next year, and asked if it was still avaliable. I sent a follow up email the next week to the manager since he didn't respond, and another follow up with the associate a week after that, usually they both respond quite quickly.

I just wanted to see if anyone had advice on dealing with this situation, I was thinking of sending another follow up next month. I'm not sure if I should be taking a hint since he specifically told me to "just keep following up" in our initial meeting.