While I agree that making you pay for their error was wrong, and it should certainly be well labeled if the instructions aren't included, I actually disagree with you. Here's my take:
I buy a lot of magazines off the rack as impulse buys. I love coming home with a new magazine to peruse. On several occaisions I have then ordered the kit for a project seen in the magazine. If I already have the magazine, why should I pay more for a kit that also includes the instructions? That would be redundant, and a waste of money. Selling the instructions, or magazine, separately, allows people who buy the magazine first to not have to pay to buy the magazine again if they don't want to.
The situation certainly could be handled differently by F&P, by lowering their prices, which seems to be a different compaint, or by charging more for the kit and including the magazine, but again, then someone like me would pay more, so I prefer buying the kit sans magazine.
Obviously I'm in the minority, and I actually don't care for F&P for other reasons, but I doubt I'm alone.
I'm sorry you had such a bad experience, though. I would be ticked if I was sold a kit that there weren't any instructions available for, and I wasn't told this until after I'd paid for and received the kit.