I keep getting 2-3 calls from this number everyday for the last 4 days and it's some guy who says "hello? hello?" and when I reply, he hangs up immediately. I need them to stop calling me.

Most of these calls are coming out of India and Pakistan.  It appears to be the ol Government grant scam from some of the previous posts.

Do a search on call blocking devices and phones.If its a cell phone, there are free call blocking apps out there including trac & straight talk.
http://800notes.com/forum/ta-5d4e343675a5629/call-blocking-devices

To report the fraud, go here:
http://www.grants.gov/web/grants/support/general-support/grant-fraud.html
Their number is listed , along with an email address, at the top of the page.
Also here:
http://www.consumer.ftc.gov/articles/0113-government-grant-scams

http://www.usa.gov/

To file complaints on Foreign company's and scams:
Read up on it here:
http://800notes.com/forum/ta-d20d86fdc3e145c/reporting-international-scams
https://www.econsumer.gov/#crnt
eConsumer.gov: Report Your Complaint
E-mail: econsumerwb@ftc.gov

http://www.stopfraud.gov/report.html
http://www.fraud.org/

They leave an intentional recording that mimics a hangup signal. Don't be fooled, they are testing to see if someone picks the phone up to hang it up. This gives them data that someone is home at that time. Just let it time out to the answer machine.

Number don't exist when I call back. They Jeep calling back 2 back and not leaving a voice message. Very aggravating..

Keep not Jeep