Basically, their UK support centre have totally ignored me - numerous emails, and waiting 24 hours (as suggested by someone in the US support side) gets nothing.
What is the point of a 3 unconditional year warranty if they won't even reply?
Time to just send back to the dealer for a credit.
Just to add, the dealer, handtec, have not replied after 24 hours either.
Update: The CEO of Sonim has been in touch with me this evening (aren't blogs fun), and we are discussing how this can be improved, so watch this space!!!