So what happens is that the person who sold it to you did not remove it from the inventory it was in.
In this case, you need to contact the person who sold it to you and ask them to remove it from your current inventory.
Unfortunately, not even Meraki support can help you with your case.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.