So, I found after e-mailing Overclockers.. they can't do anything because 'my order did not qualify as stock was exhausted before your order was placed'. This makes sense because if OcUK only had 1000 codes, they gave them ALL to the 3080 pre-orders on the 17th Sept.
I also e-mailed ASUS Support whom said they aren't directly dealing with their promotion, the same goes for the ASUS_ROGUK twitter page. They both however referred me to this page on their forums;
https://rog.asus.com/forum/sendmessage.php and stated that the site administrators are dealing with this directly.
Their site is extremely buggy too, I kept getting errors when trying to hit 'Send' stating 'Access is Denied' etc - By the time these issues are figured out the promotion will be closed and I'll be **** outa luck
Just playing the waiting game in hearing back from them now, other than that - I've found that even though the promotion is a world-wide promotion. The method of submitting your Serial Number, PPID and other details are restricted to a small handful of countries that doesn't include the UK or the EU or even the States for that matter.
I can't see why not considering we can verify our purchases, if they're still giving out codes providing the promotion is still active - we should be able to get one.
Will continue to update here on where things go.