They called my cell phone.  Called back on office phone.  They asked for the number they called, I didn't give them my number.  When I asked what they did, was told they couldn't tell me without giving them my phone number.  If I called McDonald's, I bet they would tell me they make burgers without giving them my phone number.

I bet if you called the NSA, they would require a lot more than your phone number before telling you what they do.

Also got a call from this number but did not answer it, they left no voicemail. This is a brand new phone number so I assume its a bogus call.

Keeps calling our office over and over again. We either answer and they hang up on us or we don't answer and they don't leave a message.

They were asking by name for a relative of mine and I asked who they were, they wouldn't give me any info on who they are or what they do or why they needed to be in contact with this relative.