Can't activate Windows "The product key was already used"

[Windows 10]

Hi,I want to activate Windows with a product key I bought. I have installed Windows 10 several times on virtual drive(in Parallel Desktop and VMware fusion) in Macbook Air. Now I delete all virtual drives and use bootcamp to install Windows instead. And I can't activate Windows. It said that my product key was already used. I can't find the way to deactivate because I have already deleted all virtual drives. I have called microsoft and did enter installation key with the automatic response but it said I can't use this activation.How can I solve the problem?

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