Here is the process I followed to get my serial numbers for an Elements 13 bundle purchased at Best Buy a few months back, starting with the getserial URL in Step 1:
https://helpx.adobe.com/x-productkb/global/redemption-code-help.html#purchasedproduct
You can only redeem the redemption code once to get the serial number so make sure you write down the serial number, print it, and/or copy/paste into a document for later reference.