There is a certain amount of uncertainty as to which script the Torah and Tablets of the Ten Commandments were originally given in. There is a difference of opinion cited in the Talmud Yerushalmi, Megilla I:9. One opinion is that the Torah was given in "Raatz" (identified as ancient Hebrew script) while the second opinion is that the Torah was originally given in Assyrian script (Ashuris). Ashuris script was extremely holy and when the Jewish People sinned with the golden calf, Moshe Rabbeinu started using "Raatz" instead, because its letters were less holy and less susceptible to misuse and defilement.
By the time of Ezra, at the beginning of the Second Temple era, the secrets of the holiness of Ashuris were not widely known because the script had been forgotten. Ezra reinstituted Ashuris which is the script that is used today. According to the first opinion Ezra was the originator of the use of Ashuris.
Since we are unsure which script was the original one, we do not make any changes. However, the Talmud states in the name of Rabbi Levi, ibid., that according to the first opinion the "ayin" in the tablets was suspended miraculously while according to the second opinion it was the "samech" was miraculously suspended. We do have versions of both scripts and all the letters of the Aleph Bet are in both languages, the only difference being the script.
