Ha. It makes no sense because she did call the number IMO, and that's one of the reasons she was so freaked out.
On July 3 at 11:52 a.m., Cindy called a 321 number, which I speculate was an fake number given to her by Casey as "Zanny"'s number, because it was created by switching two sets of digits in a real number belonging to a friend of Casey. After calling this number (which was a real phone number of some guy who lived in Texas but had a 321 cell phone), Cindy must have realized it was not really "Zanny"'s number at all--either the Texas guy answered and said "wrong number" when she asked for Zanny, or she got a voice mail message with a male voice on it, etc. What does Cindy do after 11:52 am on July 3? She panics, spending the rest of the day trying to track down Casey, running out to Universal to "pick up Caylee", calling Fusian nightclub, calling Casey's friends, sending Lee out on a recon mission to Orlando hot spots, and finally writing her "My Caylee Is Missing" MySpace message when none of the above worked. This phone call seems to have triggered all the activity.
Then let's look at Cindy's phone activity on
July 15, the day her universe collapsed. Cindy called 911 for the first time at 8:08 pm, then for the second time at 8:44 pm. Both times she was fairly calm and going on more about her "stolen" car than anything else.
At 9:25 pm, she attempts to call the fake 321 number again. Why? IMO the conversation was going something like this, after Casey finally "admitted" that Zanny had taken Caylee:
Cindy: You gave me a fake number for Zanny! I tried it and it didn't work!
KC: MOM! Why don't you ever believe me?! That's Zanny's number! The guy who answered was obviously Zanny's boyfriend and he was lying to you because he knows Zanny stole Caylee! Sheesh! Don't you watch any soap operas??
So Cindy called the number again, presumably with the same results as the last time.
Within 15 minutes of that call, she is calling 911 again, this time in absolute hysterics over Caylee having been kidnapped and the car smelling like a dead body. Then the cops show up and Cindy calls her boss from Gentiva and cries that she doesn't know what she will do if the baby's dead.
IMO, Casey's house of cards of lies came crashing down for Cindy at 9:25 pm on July 15, when she suddenly realized that Zanny did not exist.
Further discussion here:
Cindy's attempts to contact "Zanny"? - Websleuths Crime Sleuthing Community