First 500 km Performance of my e-bike "Flyer", the pedelec model "i:sy"

After three months of riding my e-bike "Flyer", model "i:sy", a Swiss made pedelec, I have finished the 500 km mark.  Now it`s time to return to the dealer and ask him to perform the first maintenance work as requested in the instruction manual. 
My daily rides were often about 15 km.  I have ridden the bike during good and bad weather, several times in a drizzle of rain.  Every time I returned home, I had to make it climb a steep hill.  And a number of trips I did in the near by Siebengebirge, which is a mountain region of mixed altitudes between 100 and 360  meters.
How did the bike perform?
It performed very well, to just one exception.  After a few days of rest in the garage, I took the bike out for a ride and when I had just mounted it and started pedalling,  the chain came off.  Upon a qick inspection,I found that it looked rusty and needed greasing.  Presumably the dealer had not noticed the state of the chain when he delivered the bike.
I greased the chain and my bike went on smoothly as ever. I went on riding it to my great joy and perfect satisfaction.