A family member, her husband and two kids booked and paid for a cabin for a week on the coast only to find that when they arrived, another family had taken the cabin.
In the end, they had to trawl around for somewhere else to stay, managed to find somewhere and then pay again. Naturally, they are demanding a refund and I can only imagine the level of fury they must have reached.
For my part, I would probably have been incandescent.
Anyway, I'll update this post as and when...