Cheers, Sunny Guy.
Not sure why the save files are lost, it could be because of the latest update. I had to create the android version differently than I usually do. There are save files available for where 0.7 left off(free) on Subscribe star.
Not sure what the last version was you've played but there should be some really cool new events involving the characters you've mentioned.
The coming update will be rather big with lots of really changes/additional content and will come out next month-ish.
Have fun!