Reinstallation of Barclays Mobile Banking keeps previous installation's data, even after I completely remove app from iPhone I am trying to uninstall an application (Barclays application) I have installed using Apple Store and reinstall it again.

The problem is that even if I uninstall (by tapping on it and click 'X')it and redownload it from Apple Store, the app still keeps my user data and I don't want that. This happens for the first time, only with this application.

How can I specify in the apple store to forget I have ever installed this app? Can I remove this from my cloud or remove any cookies or cache memory or anything else? 

I am using iPhone 6s, iOS 10.2 if that's any help.
In the Barclays app, go to Settings → Cancel my registration and follow the instructions.