Acknowledge the problem, keep customers updated, an apology for the inconvenience (phones calls, emails, multiple visits to the dealer 50 miles away) and potential danger caused by the failure.Well other than taking back the bike and giving you another one. What else is it that you want them to do? Maybe grovelling?
I have even had to change my insurance because BMW Motorrad Insurance underwriter have decided the bike is an "unacceptable goup", this has doubled my excess as I've had to go to Bikesure.
I'm quite sure I won't be the first person coming on here and explaining the same problem, maybe they'll end up seriously injured because the bike has stalled immediately in front of a truck that expected them to move off at speed.