How not to make apple crumble

A customer in a small, independent delicatessen asks whether they have an apple pie available, freshly-baked but ready to go now. The proprietor replies that unfortunately they don't, but says he could certainly add one to his baking list for her, ready for collection tomorrow. The customer decides that's too long to wait and remarks that in any case the price seems a bit steep when she could easily just make an apple crumble herself. She buys some rolled oats, a bag of flour and several cooking apples, and asks the shopkeeper whether he has any advice on crumble baking. He mentions that it's good to stew the apples a little beforehand but cautions against overcooking it, and wishes her the best of luck with hers.

The next day the customer returns and berates the shopkeeper.
   "Those apples you sold me were horrible, they're really bitter. And there must have been something wrong with the flour or the oats, the crumble was completely dry and tasteless. What kind of refund can you give me?"

The shopkeeper, somewhat taken aback, apologises and says if there is a problem with the flour of course she can have a refund, but he's not had any other complaints, and he even uses the same flour himself. He enquires what kind of sugar she used in the crumble, and how much she added to the cooking apples.
   "What, you need sugar in crumble?" she replies. "You forgot to give me any sugar yesterday when I asked you how to make it."

Trying to remain polite, the shopkeeper explains:
   "Well, to he honest I assumed that if you were making it yourself you'd know more or less what ingredients were needed. We do sell recipe books if that would help..."
   "No, no, they're too expensive. I'll just take that bag of sugar you mentioned and try again this evening" says the customer.
   "Certainly, madam" says the shopkeeper, "that'll be £1.50 please".
   "Oh." says the customer, clearly displeased. "Doesn't it come with the apples, seeing as they're so bitter?"
   "No. Er, no. It's a separate item I'm afraid." says the shopkeeper, almost lost for words.
   "Can you at least give me a refund on the apples, seeing as they're wasted now?" the customer persists.
   "Well I'm sorry, but no, not really." says he. "The apples themselves didn't really have anything wrong with them did they?"
   "I'm not stupid" retorts the customer, apparently offended. "I can cook pasta and I've made loads of pot noodles. I've just not baked an actual crumble before. I don't suppose you could just quickly show me how could you? Or just quickly do it for me now, seeing as I'm buying all the ingredients from you?"
"I'm really sorry, but I don't have time". Says the shopkeeper. "I've got loads of orders for other customers still to make, and this gentleman here is waiting for me to serve him".
But fearing that he's now sounded too unhelpful, before the customer leaves the shopkeeper just checks whether she's got enough butter for her crumble mix.
   "I need butter as well?" asks the woman, incredulous. Then a suspicion crosses her mind: "You're not just trying to sell me more stuff now are you?"

Remembering the customer's original request, the shopkeeper decides to change tack. He gently suggests:
   "If you prefer, I could bake you an apple pie for tomorrow. In fact it might even work out cheaper than separately buying all..."
   "Oh yes, I saw your pies yesterday" the customer interrupts, "but then I found out you can get them in ASDA for 59p."

* * *

Does the customer sound unreasonable?

Substitute:
"delicatessen" for "bike shop";
"flour", "oats" and "apples" for "wheel", "tyre" and "inner tube";
"sugar" for "rim tape";
and "butter" for "tyre levers";
and all will become clear.

Funny what's considered acceptable in a bike shop isn't it?