Case When with Boolean not equal

Case When with Boolean not equal

How can I write a case statement where if something does not equal something - then?

Here is what I have:

CASE
WHEN "2024 Seth Project 1 Item Cat"."Item Cat"  != 'INSTALL' THEN ("Sales Order Items"."Quantity" -"Sales Order Items"."Quantity Invoiced") * "Sales Order Items"."Item Price (BCY)"
WHEN "2024 Seth Project 1 Item Cat"."Item Cat"  != 'PROG' THEN ("Sales Order Items"."Quantity" -"Sales Order Items"."Quantity Invoiced") * "Sales Order Items"."Item Price (BCY)"
WHEN "2024 Seth Project 1 Item Cat"."Item Cat"  != 'SLA' THEN ("Sales Order Items"."Quantity" -"Sales Order Items"."Quantity Invoiced") * "Sales Order Items"."Item Price (BCY)"
WHEN "2024 Seth Project 1 Item Cat"."Item Cat"  != 'SHIP' THEN ("Sales Order Items"."Quantity" -"Sales Order Items"."Quantity Invoiced") * "Sales Order Items"."Item Price (BCY)"
Else 0
END as "Product",

This doesn't seem to work at all...