Usually we have to escalate this if you are trying to get the domain working on a direct Cloudflare setup and can’t contact the old provider.
In this case, the final reply from a staff member is this:
Shopify should be able to get this sorted for you. I don’t understand why they would be refusing to help a customer and directing them to a company with who they have no relationship.
I’ll escalate your issue as I did with the previous one, but I’d imagine the answer will be to contact the two partners again.