I don't have a dog in this fight, but maybe a fresh pair of eyes can lower the temperature a bit.
I think a lot of the heat in this thread originated in a few poorly chosen words. The original poster started out by stating that Heller had the "worst" customer service. I think that was intended rhetorically. (Surely the OP didn't mean to imply that he had tested out all the companies' customer service and concluded that Heller had the worst.)
I also don't blame the OP for feeling that Heller shafted him. Leaving out a hull half, in a kit that costs over $100, is an inexcusable mistake, and Heller should have corrected it immediately.
I don't know just what's going on at Heller these days. For a long time I had the impression that the company had gone out of business. For a while Airfix was selling some Heller kits (including the Victory) under its own label. Then, within the last year or two, Heller kits started showing up on the "newly arrived" pages of some of the distributors. And as of two minutes ago, Heller had a website up and running: http://www.heller.fr/fr/ .
That website is interesting. The visitor can choose between text in French and an odd form of English. (H.M.S. Victory, Le Soleil Royal, the Preussen, etc. are categorized as "sailboats.") There's a page of "new items." I can't speak for the cars and various other varieties, but the ships and aircraft all seem to be reissues from at least thirty years ago. (Those 1/24 classic cars, as I remember, were mighty nice kits; I imagine car modelers will be glad to see them back. Those nice 1/400 French and German warships are there, too.) I get the distinct impression that Heller has been through a lot of changes over the past few years; maybe kpnuts's parts request fell through a crack between management changes. But I don't actually know.
One thing that's pretty clear from this thread is that different modelers have different experiences with different companies at different times. I've had relatively few experiences of that sort myself, but the ones I have had have generally gone ok. I've never tried to get a replacement part from any of the East Asian companies; I've had pleasant experiences with Revell and Airfix.
And a couple of weeks ago I indiscreetly left the instruction book for my current project, a Model Shipways fishing schooner, on the floor, where my cat pee'd on it. The kit has been out of production for some time. (It's a fine one; I wish it would come back.) I e-mailed Model Expo's customer service address, saying I'd understand if no replacement manual was available, but that I'd be happy to pay for one if the company had one lying around. The following day I got a cc'd e-mail from the president of the company, Marc Mosko, to a lady in distribution (or whatever department it was), asking her to send me a copy of the manual. The day after that, she sent it to me - no charge - as an e-mail attachment. So I printed out the attachment and saved it to my hard drive. If I ever lose the hardcopy, or my feline landlady leaves me another message, I'll just print out a new one.
That's what I call customer service.