I had the exact same thing happen to me. So far
I have gotten 2 calls from this #  1 day apart.

I have been getting a lot of spam calls lately.
Thank god for the jailbrake iPhone app iblacklist.
If you are a iphone jailbraker I would get this app

Just today I received a call & they left no message @ about 1pm. When called back using *67 they answered & asked to speak to me by Name. The girl was nice & polite & told me they were calling about my interest in going back to school, I told them I should already b on their no calling list. She once again was very polite & stated she she would add me. Scary that *67 no longer works for blocking caller ID...