I`ve heard of a similar incident some years back, but in stead of diverting because they were lost, the crew actually thought they were at the right airport and landed!Not getting through to ATC on the frequencies (of their destination airport) they assumed they had a radio failure and plugged the numbers in the transponder.Of course, by doing this all hell breaks lose with the radar controllers who can only monitor the flight as it flies towards what it thinks is its destination.
Upon landing, and again trying the ground control frequencies, they get a hold of ATC who asks them "What is the nature of your emergency?"
To add to the confusion, the passengers have begun to notice that they aren`t where they`re supposed to be, and since they have not been informed of any diversions, some of them begin to panic fearing that they have been hijacked!
Luckily this doesn`t happen too often, and I guess the crew were a bit bashful afterwards too.Not to mention a not so impressed management...
Don`t laugh - it could happen to you too!