This was/is a domain account, right? @yourdomain.com? You upgraded from the free "google apps for your domain" account to a paid workspace account, and now you can't downgrade? If that's the case, that's unfortunately works as intended - that free domain-level tier doesn't exist anymore, so anyone who is on it (myself included) who starts paying and thereby upgrades to one of the current SKUs, can't downgrade to a SKU that no longer is offered.
This was/is a domain account, right? @yourdomain.com? You upgraded from the free "google apps for your domain" account to a paid workspace account, and now you can't downgrade? If that's the case, that's unfortunately works as intended - that free domain-level tier doesn't exist anymore, so anyone who is on it (myself included) who starts paying and thereby upgrades to one of the current SKUs, can't downgrade to a SKU that no longer is offered.