Scammers threatening to get you arrested if you don't call them back

Called and left a threatening message about getting arrested if you do not call back within 2 hours.  Says they are a collection agency (I do not owe anything). Could hardly understand the message as it was being yelled so abnoxiously into the voicemail.

Just got the same message.  Caller is nasty.  I hate to think of some poor elderly person getting this call and being terrified.  Shame on them!  Total losers!

Received a recorded message about a problem with "Revenue Canada" and that I would be arrested by the "police" at my home in two hours if I did not return the call.  What Revenue Canada?  Which police?  Hard to understand the details, as the caller spoke quickly and not particularly clearly, but he did sound serious.  This is NOT the way that the Canada Revenue Agency (the name 'Revenue Canada' is long gone) or the police work, especially with regards to arresting folks on behalf of a charge from a federal government agency.  A fantasy scenario, but I can see where it might confuse some people or, perhaps, worry the few who cheat on their income taxes.

I called them back and wanted to see who it was so just in case I blocked out my number and the Indian person was so mean and said we dont accept anonymous calls bye