Doesn't seem like Garmin really cares much about the Dash Cam products - there is not even one forum dedicated to them - despite the fact that they are in the third generation.
You will get more support here:
https://dashcamtalk.com/forum/forums/garmin.67/
How is it stuck in American English? Are you saying you can't change it in Settings? Same with VR. Often after a software update you need to reset stuff.
Have you tried reading the manual http://www8.garmin.com/manuals/webhelp/dashcam45-55/EN-US/GUID-57CE1EF1-B4B1-42A4-BE75-304134636E5D.html