Thank you all for your replies. I have got the answer I need.
I found that I have not really learnt my lesson after being misled by the wt for 16 years.
Now christendom churches just pick a verse from the bible and throw it at me and I was shaken. I did not check the context. Deegee's short answer woke me up. What was Isaiah prophesying about? His time or centuries later? The answer is just a verse before it..."within 3 years" (Isaiah 16:14) So he is not talking about what will happen to Damascus centuries later but what will happen within 3 years of that prophecy! So that prophecy obviously didn't come true...Damascus is still inhabitable!