When changing devices or taking some account actions, it might occur that players lose access to their game accounts. Each player can easily self-service this process and recover their accounts if they are linked to Facebook.
Keep in mind that this process is only applicable for iOS and Android devices. To recover your account, you can go to "Options > Settings > Link Account > Connect With Facebook". (Step 1) A new pop-up window will appear which should contain "Confirm" and "Different Account" buttons. If the account being shown is already the Facebook account you linked to the original game, then you can go ahead and select "Confirm"(Step 2).
(Step 1)
(Step 2)
However, if you were using a different Facebook account to connect with game and save your progress, then you can change the Facebook account by clicking "Different Account" and the system will let you choose.

If you’re unable to recover your account using Facebook, you might need to get support from one of our Customer Service Agents. To speed up the process, an automation is in place to help identify those users who are requesting to have their accounts recovered. We will need specific information from the player to be able to find and recover the account. We might need a store receipt showing either an in-game purchase or the activation of free trials, this will help us establish account ownership. Your information will not be used for anything else besides helping us locate the account and restore it.
Please provide all the information prior to engaging with one of our Agents. The automated messages will look like these:
For those players without any purchase (and that do have activated free trials), the required screenshots will look like this (example "A Survivor's Club Membership Trial - Android or downloading the transaction receipt for iOS).
Thank you for your cooperation and we hope to see you back in-game!