"Childish ... They know they messed up."
Deion Sanders was PISSED after his opponent trolled him after beating his Jackson St. football squad over the weekend ... slamming Alabama St. officials in a scorched earth rant.
The Pro Football Hall of Famer -- who took over JSU's football program just a few months ago -- suffered his first loss of the season on Saturday in a 35-28 nail-biter.