Well I like the idea. The trouble with all the suggestions which involve acts of vandalism or criminal damage is that they could ruin a pilots career. On the other hand, Excel's employees are unqualified toe-rags with nowhere near as much to lose.
We need to focus our attention on Manchester airport who have sanctioned this extortion racket and who almost certainly are getting a large cut of the proceeds. Write to/fax the airport MD and lets keep hassling him until this greedy scam he has started is no longer worth the bother.