Do you mean door HATCH or Latch? I guess I am confused on if you are talking about the driver or passenger door or your back hatch?
I had trouble with closing the driver and passenger doors at first. It turns out, after some trial and error the doors are so light and the smart is so air tight that you have to just short of slam them to get them shut. I found that cracking the window on the door that is already closed helps tremendously.
Now, if you hatch wouldn't close? Have them check for the alignment problem a few smarts have, and generally I either just allow it to drop shut from about 6 inches or close it and give it a good push in the center bottom edge of the back hatch window. Either generally do the job. Again I think it is because of it being so air tight. (I don't guess the carbrios would have this issue... just the coupes and the pures)
Good luck and hope you get it back soon. I can only image what it would be like, being without my smart. I would go nuts.
Happy New years all! Be safe and kind out there...
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"Where there is faith,
There is Love;
Where there is love,
there is peace."