That is an invalid area code, so obviously someone has "spoofed" the number so you can't find out who they are.  If your phone has a "block" feature on it, see if you can block the phone number.  In any case, if you're being harassed, please do contact law enforcement.  To trace a number -

Instructions
1. Hang up your telephone when you receive the threatening call and pick the receiver up again. Listen for a dial tone.

2. Dial *57. When you dial this number make sure that you do it immediately after the threatening call has been made. If you do this a couple of hours after the threatening call, the service might trace a different call. According to harwichpolice.com, if you have a rotary dial phone you should dial 1157. There is a fee for this service and you may have to pay your phone company upfront fees or pay every time you dial *57. Contact your phone company for specific details.

3. Listen to the announcement that comes on after you dial *57. The announcement will confirm that you have traced the call successfully. The traced number will be sent directly to the phone company and the telephone company will record the call.

4. Obtain an authorization form. Pioneer.net states that after you dial *57, you will have to call the phone company to verify that you activated the call trace. The phone company will send you an authorization form which, according to privacyrights.org, must be signed before the traced call is given to law enforcement officials for investigation.

5. File a police report with your local police department. The police will work with the phone company to investigate the traced calls and the caller.

Read more: http://www.ehow.com/how_5836177_trace-threate ... l#ixzz31wOFB9zn

please, please, help me find out who's phone this is 333-749-3299 as I have received a call threaten me of death and my family and I are extremely horrified by this, we don't know what to do...

thank you,

jesus martinez