APK Re-Install Won't Clear Data

Hey;

I'm developing an app that is a shell in which a user will purchase and load business information from 29 separate, purchasable regions in the US. These regions are database driven, and I'm still modifying the database for 2014 data. This is a test environment. The problem I'm having is that once I've simulated the purchase of a region (let's say, Chicago), my device apparently caches that data, so that when I update the database, the updates don't push through. I've tried clearing the cache on the app, erasing all theapp data, and disabling the Backup & Restore feature on the device, then completely uninstalling the APK. But when I reinstall a the APK from scratch, it installs with the Chicago region already showing as having been purchased, still showing the old database data.

Question is, how can I get the APK to reinstall as if for the very first time, with no previous purchases or downloads, so that it pulls fresh data from the DB?

Thanks.

Cayce