App updates automatically even after uninstall?
This seems to be a bug. Try this:


Open Play Store.
Navigate to My Apps, then go to the All section.
Delete the app from your account (usually by a small X in the top right corner of the list entry). 


See diagram below:



If it does not give you the X to delete the app from your account, click on the app in that list and uninstall it from the app's Play Store screen.