Vowels

GOD by his will has protected Quran in vowels too. For example see verse 35:28

[35:28] ومن الناس والدواب والانعم مختلف الونه كذلك انما يخشى الله من عباده العلمؤا ان الله عزيز غفور

[35:28] Also, the people, the animals, and the livestock come in various colors. This is why the people who truly reverence GOD are those who are knowledgeable. GOD is Almighty, Forgiving.

Word God must be with Fatha (Allaha) in this verse. If in this verse, word God be with Zama (Allahu) then meanning of verse is false and is against quran teachings.It show us that vowels has been protected by GOD too.