I have exactly the same problem, first did Tripoli quest and then went up to London for the quests and now I can't get any further because the quest is canceled.
Magellan & Marco Polo
All you can do is contact support - and TRY to deal with them - but there is no fix or way to bring back your character's quests that I have heard.
However, a report to them will let them know/remind them the bug is happening again.
VC CUSTOMER SUPPORT LINK : http://service.igg.com/
and by the time you do that you might as well have started a new character.
I suggest to all new or old players that have not done the quest line in a while to
follow the guide as you do the quests:
New / Beginning Player Start and Quest Line Guide
sorry the bug was fixed but before that it was broken in this way for over 3 years...so it probably will not get fixed again knowing IGG.