My Item Purchase Code is locked

Please note that according to Envato Standard Licenses:
1) “Number of end products” you can build with a single license is “1”;

and

2) “you can’t use … Standard Licenses on multiple clients or jobs”.
– https://themeforest.net/licenses/standard
Also, note that the license “generally … is not transferable”: https://themeforest.net/licenses/faq#license-transferable-a
It means that if you have used your purchase code on one website, you should not use it on any other website(s). Even if the original website went offline.
Our system detected that such a purchase code was used on multiple unique domain names (excluding most common dev and staging addresses). Such usage violates the terms of Envato Standard Licenses and, by extension, our copyright. Therefore, this purchase code was automatically locked.

These are the license terms (which were accepted on the purchase by all buyers). And, unfortunately, we will not be able to unlock such codes.