I had one guy on the phone for about 15 min & got him to admit he liked gay butt sex at least 3 times in that call. If you can fake a good Hindu accent, you can certainly turn the tables on them before they finally get frustrated & hang up. & if you can, hire a Grey hat for your IT department. Them guys can rig a phone through their computer & back hack the VoIP if they are good.
Back hack a scammer is not illegal, it's safety for your business.