The Adventure of the Phantom Chocolate Covered Peanuts

When is a packet of chocolate covered peanuts not a packet of chocolate covered peanuts?  When you try to buy it in a Tesco Metro, apparently.  The other day I was in the aforementioned Tesco Metro when I noticed that the chocolate covered peanuts had been reduced in price, so I made a snap decision to buy a pack with my newspaper, (which was my main reason for going in there).  Taking them to the cash desk, the newspaper's barcode scanned without problem, but the peanuts failed to.  After attempts to enter the barcode manually, the youth manning the till told me that the product I was trying to buy was not on the system, so as far as the store was concerned, didn't exist and therefore couldn't be bought.  I tried pointing out that the packet of chocolate covered peanuts was right there, in front of us both and therefore did exist, (I mean, we both agreed that we could see it, so it wasn't an hallucination on my part).  When this didn't work, I tried pointing out that the peanuts must be for sale as they had a whole bloody shelf of them, prominently displayed with a clearly marked price.  Moreover, the packet was clearly marked 'Tesco', so was an own brand product, so how could he claim that it didn't exist?  What was the alternative explanation for their presence?  Was someone sneaking into the store with packets of chocolate covered peanuts with fake Tesco packaging concealed about their person and secretly placing them on the shelves?  Why would anyone do that?

Of course, it was all to no avail.  The peanuts didn't officially exist.  Fearing for my sanity, let alone blood pressure, I paid for my newspaper and left the shop, leaving the supposedly non-existent nuts behind.  It was one of those incidents that turn you into a raging Luddite, railing against modern commerce where, if something isn't registered on a computer system, then it doesn't exist.  Whatever happened to the good old days of mechanical tills where the cashier entered the price manually and those little flags popped up with the total and a bell rang?  I was left pondering whether this chocolate covered peanut phenomena was simply a local glitch confined to that particular Tesco Metro or whether it was nationwide.  If I had gone to the main Tesco on one of the edge of town retail parks and tried to buy an identical packet of chocolate covered peanuts, would it too have been deemed to be non-existent when i went to the check out?  I honestly couldn't be bothered to find out.  Eventually I bought some chocolate covered peanuts elsewhere: I was in one of my local Lidls (we have three) later in the week and they had chocolate covered peanuts for twenty pence less than Tesco's reduced price.  For the same amount.  I can't deny that I experienced some trepidation when they went through the check out, but they went through with my other items without incident.  So clearly chocolate covered peanuts do exist in Lidl.