ACS Legal Department Harrassing calls Agoura, California

My 14-year son has received numerous harrassing calls from the "ACS Department" regarding some "problem" with a social security number.  They asked for a James Parker but regardless of the multiple times my son has said that was not him, they insist on calling him back. 

The caller said his name was Steven Lee (I doubt).  They have called in using numbers 818-483-4979 and 462-249-8845 and gave a 917-284-9293 call back number and to ask for a Danny Johnson. 

I called them back and told them that they were harrassing a minor and I was going to call the police...click...they hung up on me.