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: [email protected]

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