Still receiving calls from "senior graduation"

So since I last posted about this, they have been calling me over and over again and I've been ignoring their calls over and over again. What if it were an important call?

Well, usually they would leave me a voicemail (health centers, ISU billings, etc.). These people on the other hand, just calls and when I ignored them, they move on to the next person on their call list and try calling me again the next day.

I wonder how long they can keep this up. All I have to do is just push one button to ignore their calls.

And, if it's REALLY important, they would've called twice. So I would know when to pick up and when not to.