Rescinded Transfer Admission letter recieved today due to lack of major requirements ! Help!

My son just recieved a letter in the mail (postmarked May 24th. but letter is dated April 13th.)
It says he didn’t meet the conditional agreement terms required for admission. It says " a review of your transcript shows you have reported History 103 & 104 as major related coursework but the courses do not articulate. Your admission to cal poly has now been cancelled." If you wish to appeal please go to … (A Link with how to appeal decision)

So after much searching I found a page saying that the transfer major requirements are US History and World History and Western Civilization to 1500 and since 1500 but the classes he took is called World Civilization to 1500/since 1500. So I imagine were thought those were one in the same if we ever saw this.

Do we have any recourse? We don’t get this letter until after we’ve passed most deadlines, and turned down all the other colleges?
Isn’t this something they should have reviewed BEFORE THEY GRANTED HIM ADMISSION ?
We were under the impression that we only needed to complete the GE-B plan and he did. So he now has a History AA-T, a Admin of Justice A.S-T and a Liberal Arts Social and Behavioral Sciences A.A.
63 units completed
he took all the required transfer requirenebts that apply to a cal state so I don’t understand how this school requires 2 additional history classes to get in with a history transfer general Plan. Isn’t that a guarantee for a CSU that it meets all the requirements for a history transfer?
He took seven history classes, 21 units out of his 63.
Of course we get this on a holiday weekend and can’t call and talk to anyone.
Could it be just that they haven’t received his spring transcript that shows he earned his AA-T? Or is he really out of luck?

Sorry to hear. How did it turn out?