John,
Really sorry to hear about this issue.
Sounds like a battery problem to me but my tech team would be much better than I with diagnosis and resolution. Nothing beats a phone call, so hopefully you can both speak in detail today.
If a battery fault is diagnosed we will of course send a brand new replacement to arrive next working day. If not, we will find the problem wherever it is elsewhere - (never been beaten yet!)
Just to clarify one point however : we have two full time mechanics doing PDIs on all our bikes. Each takes an hour to run through a 50 point checklist for both mechanics and electrics. We can't however really ride the bike before despatch - customers would not want us to and it would add time to what is already a lengthy check process, not to mention wet days which would prevent this. So it is inevitable that obscure problems, like yours, or intermittent ones, would not be evident during our checks.
Thankfully such problems are very rare.
Lets hope we can get to the bottom of this swiftly.
Kind regds, Hatti