Where to get a Melodium 42B fixed ?

Hi all

I recently got me a Melodium 42B. Alas, there is a problem: the metal housing resonates very noticeably. At least I've identified the issue: it is the exact same resonance sound as when I ping it with my finger. Still, I don't know what to do about it.

Where can I get quality maintenance done on it? Preferably within the EU. Or elsewhere if there is no other option.

Thanks