[Lio]

"Employee" is a bad term to use here, I assume you mean contractor.

If you're acting as a contractor then you are specifically not an employee and you shouldn't let anyone at your client refer to you as such or try to control how you work except via the terms of your contract.

That means for example, you ask to take leave. You tell them that you are not available on certain days. It a subtle but very important difference.