I blacklisted them on my phone using an antivirus I installed.  It's nice because if they don't leave messages then you will never know that they called.  Goes straight to VM without letting you know you have a missed call.  I do this with all phone numbers that are bogus and don't leave messages.  Obviously if they leave a VM, then you'll get the notification but it's better than hearing your phone ring constantly.  I never answer numbers I don't recognize.

I also got an email as well as several calls on my cell.  Didn't even open it, marked it directly as spam....

Called me 6 times today, the last time at 11:18 pm. Never left a message.

I believe it is, in fact, a telemarketing call on behalf of University of Phoenix. The calls started right after I visited their website to inquire about continuing education. They do not leave a message, but do call often.

Calls several times a day with no message

I've gotten 3 calls within the last few hours, but no voicemail. I figured if it was important, they would leave a VM.

This number calls me repeatedly and does not leave a msg. I called the number back and a rep from the university of phx answered. Probably from when I was researching grants. Hope this helps.

I continuously get a call 2-5 times a day. Without messages. It has been about 2 weeks of this. I will probably give in and answer soon.

I, too, keep getting calls from the same number and they never leave a message.  I also do not answer any calls from phone numbers I do not recognize.  If it was a legit company trying to get a hold of me, they wouldn't have a problem leaving a message for me to contact them.

They are a harrasing-type  caller, every day!!  2-3 times  a day.
I just do not answer.

the number belongs to Global Crossings Local Services Inc. I looked up their company at www.globalcrossing.com it appears to be a company which offers telemarketers ways to contact peoplem but that's just a guess.  I simply don't ever answer phone numbers I don't recognize, if it's a legitimate company doing legitimate business they will leave a message with all of their information.  I don't give anyone the benefit of the doubt too many scammers & con artists out there.  My suggestion is don't answer the phone if you don't recognize the number & if they don't leave a message, they probably aren't legit & I would just delete the number & not worry about it or goggle it & report it.

keeps calling w/o leaving a message