If you have issues with them, call them back and while the system is talking press and hold down 9 until it disconnects. This might help but i just tried it so I hope it does.
I've received 23 voicemails in a week from these guys even though I pressed unsubscribe/remove from call list. Robocallers claiming you are elligible for student loan forgiveness through new government policy. Never heard of such a thing, but wouldn't it be nice!