On your Adopia account page click My Account.

Under My Account Information, in the Billing Info section click View of Update

Under Opt-In Settings, scroll down to Customize Unsubscribe Page. In the Customize Unsubscribe Page section you can edit the way you'd like your 

Thank You page displayed. You are are able to have your logo and website URL displayed and you can pass whatever user information you'd like to include 

about the subscriber as well. Click Save when finished.