Can't update Play Store

[Android Central Question]

I formatted by Lenovo Tab 2A-7. It went back to an old version of Play Store. I clicked on the update button, and it said "A new version of play store will be downloaded and installed." The next time I clicked on the Play Store icon, it said "App isn't installed." Now, it works if I clear the app cache, but it goes back to the old version, and after a few minutes it says "App isn't installed" again.
I tried installing using an APK, and it says "Installing" for like 15 minutes , before finally saying "App not installed"
What can I do?

 

[B. Diddy]

Welcome to Android Central! What version of Android is it running? Go to the Google Play Services in the Play Store website on your computer, and click Installed, then look in the device list to see if that tablet's Play Services can be updated: https://play.google.com/store/apps/details?id=com.google.android.gms&hl=en_US