It sounds like you are in a difficult situation...

I bought a used Autel MaxiDiag Elite MD802 which had already been registered to another person. I was unable to update the software, because the device was not registered to me. I could not register it to me, because it was already registered and the Autel website does not allow you to override this or re-register a device. In the end, I contacted support.eu@autel.com for assistance. Previous communications had failed, but this time I got a response from someone who helped me re-register the device to my profile.

Finally, after 5 years of ownership, I have been able to get all the latest updates for my MaxiDiag!

Perhaps contact support using the above email and explain your situation. They may have some advice. Just be aware, you may have to pay for a replacement. Companies like Autel make revenue from software sales more than hardware, so it's likely that you'll have to pay for a software replacement.

Good luck!