Office 365 Activation Emails from Dell

When I purchased my Inspiron 5575, I also purchased Office 365 Personal. When I activated and installed Office I did so through Microsoft Office 365 website. I already had an account setup but did not have any active products. So Office installed fine and my subscription shows up properly. However because I went through the Office site, or so I am assuming, I cannot activate through Digital Locker as the product key displays an already used key message. Now I keep getting Emails from Dell asking me to activate the product I have already activated and installed. The question is..anyway out of this loop so to speak?