Got my Rocket back from the dealers yesterday on the 13th July. They did replace the TFT display and that fixed the problem with the bike not starting. I only drove it home, about 40 miles, and so far no further problems. I did ask the dealer for a more detailed explanation but he said there isn't one. Quite simply the TFT display failed completely and that results in the the bike failing as well. I asked if it was a common problem and the answer I got was, this is the first time they, (the dealer), have seen such a complete failure with the TFT display resulting in not being able to start the bike. So to conclude they said it was just one of those things.
I am not overly satisfied with the explanation but it is obvious I am not going to get anything more.
Regarding the failure of the tracker, that is due to be replaced on the 25th of July and, since it is just a plug in module, I suspect I won't get any detailed explanation for that either.