Multi-brand service desk, does it exist?

Question

Technical support

I am looking for a service desk/helpdesk where I could organize many completely isolated projects. "isolated" means that agents, tickets, and clients in project A cannot see or even know about project B, and vice versa. This is the main requirement.
Other requirements:
- there is an API
- there is a live chat
- there is support for many UI languages
​​- you can create an admin account that sees all projects
- customers can create tickets without authorization
Such requirements are due to the fact that we sell SaaS, where we want to add a service desk, but find suitable we cannot. Zendesk does not support such functionality and is very expensive. Atlassian is close, but live chat does not work there and there are links to all projects on the portal page (not isolated). Help!

Answer 1

is Atlassian cheap? ))