root access - Recover deleted app data

I'm having some trouble with an app, it is an app for a service provided by my local bank. Apparently for security purposes it is not on the Play Store and when you subscribe they send you an SMS with credentials and app download link.

I downloaded the app and used it. First time you launch it asks for credentials and activates your account, no login Activity, just the Activation Activity and then it goes straight to usual interface every time.

So I accidentally deleted the app data (meant to delete cache) and now every time I launch it I have to activate my account, which won't activate because it is already activated !!

I spoke to the bank customer service and they said I can only cancel subscription first before they send new credentials which is supposed to be done from within the app. So I'm stuck unless I can recover the app data. They are charging me for the service by the way.

I am using a rooted Galaxy Note 8.0, is there any way I can recover the data ? Preferably for free?