They installed the new vending machine in the high school by mistake.
Hervan van den Lufft, the company that delivered the machine produced documentation to prove that they had been hired to deliver to that address. The documentation was surprisingly lovely; hand-calligraphy on heavy parchment paper, with flowery language worthy of Shakespeare (the local newspaper, the Metropolitan Memo, omitted the literary reference when reporting on the story after the school's Head of English asked who Shakespeare was while reviewing an advance copy), and even illuminated capitals. An eagle-eyed reader of the Metropolitan Memo pointed out in a letter to the editor that the illuminated capitals appeared to have rather a large number of inebritated and possible drugged young people cavorting and sleeping on the crossbars of the letters but this was ignored by the paper's editors and all copies of the paper were gathered and pulped in a quiet but efficient campaign later that week. The documentation was all entirely in order, except for the oddity of the sheer luxuriant quality of it.
The manufacturer of the vending machine quickly produced a large number of examples of their standards of dockets and request-fulfilment forms, which were cheaply photocopied with low-toner photocopiers and recycled paper. Their environmental credentials were high, and it was clear to everybody that they hadn't arranged for the delivery. It was noted, much later, that they had continued to refill the vending machine for six months after the issue first came to light, but by that point no-one was interested in stirring up the past any more, and the offending vending machine had been removed, so it was allowed to slide into obscurity.
The sixth-form of the school was interrogated by the deputy-head, a fearsome woman that the students spread incessant rumours about. The one that made it past the Metropolitan Memo's fact-checkers was that she had been a lover and teacher of Pol Pot when she was younger, and had given him ideas. The sixth-formers appeared to be in rather better health than should have been the case if their rumours were true, and Miss Pyepie never seemed to even pick up the chalk, let alone a bloody soldering iron. The rumours died quickly, and it was surmised that the students hadn't ordered the vending machine.
Which meant that no-one seemed to know where it had come from, who had ordered it, or where it was supposed to be. This last fact created the inertia that led to the machine staying put instead of being picked up again and taken back to the manufacturer's warehouse on the ring-road.
The vending machine dispensed medicinal soda. The notional idea was that these would be installed in hospitals and doctor's surgeries and would speed up certain prescription medicines. Moreover, a repeat prescription would be unnecessary as the patient could simply pop in when they were passing and pick up a few more cans of Digitali-cola for their heart murmur, or Straight-up, the Viagra fizzy drink. There was a little concern expressed initially that this would lead to unregulated drug use and people auto-dosing themselves into medical comas. When the unsubsided cost of each can was revealed though, all such doubts evaporated, and instead questions were asked about how people were expected to pay for such things.
The sixth-form asked no such questions, and found the money for the cans from somewhere. All the Straight-up would sell out within two days, though no-one was ever seen with a can or would admit to buying it. More worrying, all the of the Prozacade would sell out just as fast, but people were happy to be seen with three or four cans of it, as though it were somehow a status symbol. The manufacturers later pointed out to a skeptical judge that if this little accident of location hadn't happened they would probably have never discovered that mixing Prozacade and Red Bull caused the kind of euphoria that's called oxygen narcosis underwater. Above water, it just made people so happy that they would dance in the traffic, on train-tracks, and occasionally right off the edge of high buildings.
Prozacade now comes in a little plastic package that contains a thin, but strong, strait-jacket just in case.
Parents eventually asked questions, usually only after seeing their can-recycling contributions soar, and the parents of the dead children kept asking questions. There was much talk and few answers. Finally, and with very little fanfare indeed the vending machine was taken away again.