I decide? Good. As a refutation of relativity, it's crap. Game over. Thanks for playing.
The page loads now that I am on my home computer. Your clocks are 15 light-seconds apart. All you are doing is measuring that they are 15 light-seconds apart. An observer at any position will be x light-seconds away from one clock and 15-x light seconds away from the other. One reading will always be T-x, and the other will be T+x-15 (ignoring your offset).
When you add them, x cancels out, so all observers see 2T-15. Wow. You've discovered algebra. <yawn>. Note that you have assumed Galilean transformations. Relativity hasn't come anywhere close to your dicussions, so I don't see how you can conclude that it's wrong.