Well, I'll be a monkey's uncle. Or aunt. For the last two months, I have had a penpal relationship with Opodo, the company who in September sold me the flights to and from Prague. Of course, the return flight was non-existent, as I discovered to my horror when I went to check-in online a week before in November. Opodo had sold me a non-existent flight. Opodo refunded me the return leg of the fare, but, because so much time had passed between originally booking in September and having to buy a replacement flight in November, the cost of the replacement flight had soared by three times as much. I argued they should pay the difference, as it was Opodo's fault that they had sold me a non-existent flight and then put me in a position of having to buy a replacement flight at such short notice.
I say I had a penpal relationship, but in all honesty, it was mainly one-sided. I would send off a detailed email to customer care, then three weeks later they would reply with a one-liner wanting more information. I would reply within 24 hours and then have to wait another three weeks for their reply, again wanting more information. However, eventually, they accepted my expensive outlay was their fault and said they would pay out the amount I had requested. It took five days to reach my bank account, but, yesterday, when I checked, it had been paid in. So it is possible to take on a faceless organisation and get your fair dues. Miracles do happen.