I feel your pain.
It sounds familiar to my first (2012) Miev experience I had, they just couldn't find the problem.
After 2 months and 3 trips back to the dealer, I had enough and worked out an agreement for a new 2014 Miev.
Puey Bluey 2014 Miev
76,400 miles, 123,000 km
Blackie - 2012 ES Miev 2 years - 67,000 km / (41,630 miles)
Total Electric miles driven
118,000, (190,000 km)