Bulent, you're very helpful. I am still not sure however, if the Public Registration Office in Turkey had power to cancel the illegal marriage or whether I have to hire a lawyer to do this. The following is the (translated) letter I received from Turkey via the embassy:

"In the attached registered letter received from XX Public Registration Office, it is asked
if there is the divorcee verdict of the court or not
for Mr. X; as a condition that he cannot make a
second marriage officially on the date of xx. If there is the official divorcee verdict, it is asked to hand in copies of it and also the rejection of his marriage declaration is demanded for to be handed in to the Public
Registration Office".

After receiving that letter, I confirmed that no divorce took place and requested that 2nd marriage be cancelled. Subsequently I received the marriage booklet. I therefore assume Turkish officials from registration office obtained cancellation from the court on my behalf as otherwise they would not have issued me the marriage booklet. Do you think my assumption is correct?. Thanks.