The surround camera system I believe is only on the HSE Lux-package. Your HSE sounds like it isn't a Lux-package. As for surround cameras, be glad you don't have it. I have read nothing but complaints about it. Cameras going blank, breaking, not working at all... it's just a gimmick (impresses your friends for about five seconds) and more electronics to break.
As for the L7, I have the standard HSE and L7 was an option, the L7 only comes standard on the Lux-package. If you have the non-Lux, the dealer isn't going to pay for it, not sure why you think they would? Anyway, if you can upgrade it through the dealer, I'm sure they'll do it for a fee. But your money would be better spent on an aftermarket system.
Now, if you do have the HSE Lux-package, I believe you're supposed to get the surround cameras and the H7 as standard. So if you have the Lux-package, I'd ask why you don't have them and how they can compensate, and why your LR4 got so screwed up.
Land Rover LR4 (base)
Land Rover HSE (7-seater w/some light options)
Land Rover HSE Lux-package (loaded minus the DVD package and some other stuff that’s $$$)