Had a similar issue with my wife's new account. The solution was to go to the M&S desk in IST airport and request a solution. The solution they found was... To create a new account (!!???!!).
You might have better luck by calling TK, since it is your account, but be prepared to receive up to 5 PIN reset emails, none of them containing the user ID
I assume you don't have the card or the baggge tags...?