Read the DHS OIG fraud alert for more details.

If a Scammer Calls You

If you receive a call demanding personal information or payment, hang
up immediately. If you want to verify whether a call is from USCIS,
you may:

• Call our National Customer Service Center at 800-375-5283 to ask if you need to do anything about your case or immigration status,
• Make an InfoPass appointment at http://infopass.uscis.gov,
• or
  
• Use myUSCIS to find up-to-date information about your application.

Remember, USCIS officials will never threaten you or ask for
payment over the phone or in an email. If we need payment, we will
mail a letter on official stationery requesting payment. Do not give payment
over the phone to anyone who claims to be a USCIS official. In general, we
encourage you to protect your personal information and not to provide details
about your immigration application in any public area.

How to Report a Call from a Scammer

If you receive a scam email or phone call, report it to the Federal Trade
Commission at http://1.usa.gov/1suOHSS.
If you are not sure if it is a scam, forward the suspicious email to the
USCIS webmaster at uscis.webmaster@uscis.dhs.gov.
USCIS will review the emails received and share with law enforcement agencies
as appropriate.

Visit the Avoid Scams Initiative at www.uscis.gov/avoid-scams
for more information on common scams and other important tips.