I have been getting at least 1 call per month by an alleged DEA agent.  The area codes vary, but the story is always the same.  The fastest way I have found to relieve the stress of a hectic day is to have fun with them.  I normally start laughing, and ask them "how many poor [***] actually fall victim to your scam?'  When they start talking, I cut them off and demand to know how the hell they live with themselves?  Some continue with the same blah blah, but usually they just hang up.  
The latest was a call from Colorado, no accent at all.  Last month  is was from somewhere in Washington state, no accent.  I can almost predict when they will be calling, as I get a phone call a day or two before from some unknown person trying to sell me rx.  I regret the day 7 years ago when I ordered tramadol from an online pharmacy.  On the positive side, I get to have fun with a scammer on a monthly basis!
Good luck to all and may God bless!