Were it me I'd call the closest GIVI dealer; the selling dealer if that is possible (you did buy 'em locally, right?).
I doubt you will make any headway with the company, especially considering they are HQ in Europe.
Another option is to see a competent locksmith. I had one cut me a spare key with different cuts on each side, so 1 key would open 2 cases. The same guy also picked the combination lock on one case that had reset itself. No reason he couldn't rekey the lock in the case of the lost keys, or cut you a new key using a blank.
Ilco X226 HYD12 is the blank number on mine.
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