It's called 'caller id spoofing'. The people calling you can make any phone number show up on your caller id. They're making a number show up that charges you money if you call it and press a certain key.
At the same time they've disguised the messages on their pay by phone system as surveys. Those messages normally tell you what you're buying and how much it costs.
Check your bill for unwanted charges if you called this number back.
In response to Pete above, I don't download apps on any system, so this call may just be a coincidence in your case. Their auto-dialer doesn't care who is registered on the DNC list.
Most of the postings here state that they haven't heard anything except clicks or dead air, although one mentioned that it was a robocall about taking a survey on the nation's debt crisis (which is a ruse) in order to 'win a free cruise.'
Be aware that this is a big SCAM. The cruise is not free. You have to give them a credit card number to hold your reservation and any and all supposedly small fees that these idiots charge are NOT refundable. Do not fall for it.
These crooks are either calling from some horrid cruise company or from some sham travel agency. They are making illegal telemarketing calls and hiding behind a 'survey' to sell their crap and steal people's hard-earned money. They are using this same robo message from a lot of different phone numbers. What legitimate company spoofs their Caller ID information?
Do not give them the time of day. Hang up and report them to www.donotcall.gov.
Got a call from this number 5 minutes ago. Similar one yesterday that just read 'Austin, Texas' for the caller ID. Not sure the point of this, but they seem to be repeatedly calling lots of people.