If you are under a service contract you "might" be able to get LC-Win 4.0. It's not just the matter of you getting the CD and loading the software, the application server on the system must also match, and LC-win 4 has been traditionally bundled with the 9006.6 platform (AKA Hicom 300H Release 1.0 or something like that) which would require that you have a processor upgrade, probably an HD swap because the 9006.6 platform runs on UnixWare instead of traditional unix, and a few other things. I recently upgraded from 9006.4 to 9006.6 for a cost of about $25,000 but that included adding ACD and a bunch of other stuff, so I would assume you might be looking at about a $10,000 upgrade fee for that, considering you're already at 9006.5 if you have LC-Win 3 - Major upgrades like that are generally not part of a service contract.
Good Luck!