Keep this in mind, the next time you decide to call someone off of a craigslist ad to yell at them, scream at them, harass them with informative pleas that "your horse will sell to slaughter" (don't worry, everybody already knows), recount the religious mission you feel you're on to save horses courtesy of some dream you had (told in lengthy detail, capable of spanning hours), so on and so forth.
All of this only turns people off. Off. They shut down. They will instead go the much easier route, and take the horse to auction.
If you can't be civil, direct ("I would like your horse"), and polite ("thank you"), and can get it done within two minutes max (preferably shorter!), don't pick up the phone. Otherwise, all you're doing is putting the final nail in the coffin. And dooming that horse to auction, kill buyer, or slaughter.
If you can save the horse posted yesterday in Selma, CA (now removed!), email me privately.