I was able to successfully get most of the data back (except for this past week) by following the instructions here: https://support.microsoft.com/en-us/help/17119/windows-7-recover-lost-deleted-files
I have the same issue. I thought I was deleting a new sub-task that I just created but somehow all of my tasks in the entire account got deleted. If the information can be restored, please tell me how I can get everything back!