There is actually a long running scam in shares of Biodefense Corporation who were supposed to have invented something called a mail defender, you may have been approached by a boiler room selling their shares or a related scam.
In any case its a scam and you'll lose your money as the shares will either be non existent or restricted meaning you cant sell them.
Can you clarify if the company who called you was "Biodefense Corporation?" They push shares for a company that makes a product called the "Mail Defender"
