"Manage your booking online" - fat chance
I'm also having problems managing my booking and am frustrated by the two telephone numbers which merely refer you back to the non-functioning "manage your booking" page.
I'm due to fly on 2nd April and as yet have had no response to 2 emails (Thomas Cook's suggested alternative to the non-answered phone or problem-ridden website.)
In the hope that someone from Thomas Cook reads this thread - DEAL WITH THE EMAILS!
Deep breath - count to 10 - relax....