Removing device not working

Just moved into a new house with existing Ring Doorbell. Prior owner has removed device from his account, but any time I try to register it it tells me it’s still registered. Need to find a way to remove it and set it up

In order for it to work. The previous owner must remove it from their account. Even though they said they did, doesn’t mean they did it correctly. You can reach out to customer service to check it’s status.
Information on customer support below.