Security Role assigning to the particular user

User has attached with multiple roles like accountant, system user, budget clerk and also customized roles.

I want to disable post button in "General Journal" form , So I created a new role and disabled the post button.

When I am adding new role to that user and at the same time I am removing Accountant role to that particular user, the post button is disabling.

But when I am giving both Accountant and new role to the user the post button is enabled.

Here my concern is I want to add both roles Accountant and new role to the user and the post button should be disable , How can I achieve this?

Regards,

Sai