Alexsemi100 That's interesting. If it was properly refurbished by a Microsoft authorized Refurbisher (MAR) https://devicepartner.microsoft.com/en-us/assets/detail/mar_partner_directory_aug2017-pdf, it should have gone through the OEM Windows deployment and key-injection process to receive a fresh/new image and license key. When this happens, the device is automatically removed from ANY tenant it was registered to.
If that didn't happen, you should contact your MAR and ask them to remediate this. MARs have access to all relevant documentation in Partner Center and/or should speak to their partner account managers about this.
Also, above process is needed to ensure you have a genuine/legal license to use Windows on that device. If they didn't do this (which it appears to be), they did not necessarily sell you a genuine Windows license and are in dereliction of their MAR duties.
If they aren't a MAR, things get a lot more complicated. You should reach out to the device manufacturer's support (Surface) and open a ticket to get the device removed from the previous tenant. They will need some conclusive proof of purchase and ownership to verify that the device is, in fact, still registered to the wrong tenant. This will usually include the sales contract or invoice demonstrating a gapless chain of ownership.
Obviously, this is made intentionally difficult to prevent all too easy abuse by folks trying to "hijack" devices.
If the seller isn't able to do this for you, I would get the device exchanged for a new one.
Also, you don't need hardware to test Autopilot. A VM has a 4K Autopilot hash just as physical devices do. Use the same getwindowsautopilotinfo PS cmdlet to harvest it.
(PS. I used to work in Device Technical Sales DTS at Microsoft. I helped a bunch of OEMs and channel partners build their Autopilot offerings, so I know how poorly some of them implement it.)