Here's the solution:
Please open the File Explorer and go to:
C:\Users\***\AppData\Local\Packages\Microsoft.MicrosoftSolitaireCollection_8wekyb3d8bbwe\LocalState\UserData
If you are a guest, please go to Guest\Statistic
And the same way if you have a Microsoft account.
Than delete "Statistic.ark".
Now you can notice that game statistics have returned as they were.
Thanks to "Jack D. Pond"
http://www.windows10forums.com/threads/how-do-i-reset-solitaire-scores.4280/#post-21785
I did ths. It didn't work.