Complex sentence: When she did not return, they called her cell phone at 8:48pm and she told them that she was locked out of the arena because of its "no re-entry" policy, adding that she would find a way home and they should not worry.
Split into simpler sentences: When she did not return, they called her cell phone at 8:48pm and she told them that she was locked out of the arena because of its "no re-entry" policy. She added that she would find a way home and they should not worry.