Hey there, @Kwena_R
Bo here from Shopify Support!
Thank you for reaching out regarding this. In order to resolve this issue, you will need to contact support directly regarding this. When this happens it usually means that there is a store on the platform that is no longer active which has this domain connected, our support team can remove this domain from the inactive store for you once you send them a screenshot of the DNS Settings of the domain to prove ownership. While we’re not able to provide account-specific support via the Shopify Community at this time, we’d be happy to continue assisting you through live chat, email, or callback. Please visit https://bit.ly/3cJkx8V and log in to your account to create a support request.
Since this is the next step I've marked this reply as the solution for the benefit of others who may discover this topic. Thanks!
All the Best,
Bo | Retired Staff Member