How do I receive the refund for my Prior Subscription which was not fully used when I upgraded the Subscription?

You will receive the refund in your account from the Appstore/Google Play when you upgrade to a subscription. Psychic Txt does not have control over the exchange of money. 

Before confirming the purchase for the upgrade, you will get a pop-up for Purchase to confirm which informs that " YOU WILL RECEIVE A REFUND FOR THE REMAINING TIME OF YOUR 1-month "CURRENT" PACKAGE SUBSCRIPTION subscription.

If you do not receive your refund, please contact the Appstore support for iOS and Google play store for Android.