Firstly I am glad you enjoyed your flight to London Gatwick and were pleased with the service received on board. LGW tends to be really good and the groundstaff are always excellent in my (limited) experience. And I really mean this.
[sunrisegirl are you reading!]
I should point out that LHR is usually up to these standards, and there are many outstanding members of staff here too, however there are possibly a slightly greater proportion of weaker links.
I have still not got over the finest example of man-management shown by a purser on one of my recent flights - his colleague up front in the Domestic service couldn't really be bothered but when he saw the passion and enthusiasm of the purser he really came into his own. It was textbook British Airways. At their brilliant best.
I am very sorry to hear about your disappointing World Traveller experience. I've not flown in World Traveller since I was 7 years old so I don't know much of it any more. [I've only flown Club World and First since then].
It's always frustrating when crew forget to bring you what you want.
I hope that your return flight was better.
With best wishes,