What goods or services were they trying to sell you or qualify you for a third party for?  Don't know? Then how do you know the caller is violating the DNC list? Only callers selling goods or services or qualifying you as a prospect for a third party are required to screen against the DNC list before calling residential numbers.  Dropped calls or dead air calls like this can be reported to the FCC however even if they are exempt from using the DNC list.