I just received a call from this number.  Does anyone know who this is?

No name listed. No message left (called two times).
Called number back and system stated that it was not in service. Spoofed called ID number?

could it be nco

Same number called me three times today. Caller id said either Moscow, PA (not far from where I live), or 0000000000. With the added caller ID info, I figured I would give it another call. I got a recording of "We are TMT we sell various energy and telecommunications products. To be placed on our do not call list, press one. To receive information on a product press 2."
Pressing 2, gives the message that the user at extension 5000 is not available, than that the mailbox is full, than that there's an error, disconnect.
Pressing 1, gives a prompt to enter the number to be blacklisted (we'll see tomorrow if they actually stop calling), enter 10 digits and it says Thank You. click.

This MAY be a legit business, but they're certainly doing things the wrong way to win new customers.

I get a phone call everyday at least 2-3 times.  I just tried calling back and it said the number is not in service.  I also live in the moscow areas of PA.  What is going on?