Why would there be a flaming?
If you haven't taken the money and held on to it (which I very much doubt 100 percent) I can see no reason why anyone would flame you for not being able to supply a product due to a third party.
Dont worry about it you wont be the first or last that this has happened to dealing in third party service levels and promises. I can think of a company that promises tomorrow, next week, its on it way etc etc and so on which you have not done.
With these last batch they will be limited edition! ..... Nice one hold your head up high
A bolt on chain guide would be a great one if you are thinking of making one