Hi @AndyP
Sorry to hear about the purchase experience. Which shop was it?
We have not shipped Dwarf units to UK dealers for a long time, so the unit is likely a return.
And as it might be a return, it is likely that the USB mode is set to Windows, which is not the default mode.
You can fix it following these instructions: Dwarf Device Settings - MOD Wiki
Let me know if that helps
And welcome!!