Thanks for all the replies! While on the online chat, the rep opened a complaint for me as I wasn't happy about the firmware not being up-to-date. She told me that SG4B1000E020 was the latest version but I kept telling her that I knew that SG4B1000E079 was actually the latest (thanks to this forum!)
Anyway, I looked up the complaint and she'd raised it then closed it. I then reopened it and put in the details about the latest release etc and someone called me back; a very helpful chap called Cahal. He did say that he'd never heard of anyone asking for the firmware to be updated by them manually but along with a colleague they managed to do it and the router is now on SG4B1000E079.
