I went for a meal with family last week and used a credit card to open a tab. I paid the bill when I left and got the receipt for the amount I paid. This showed up on my credit card bill as expected but what I didn't expect was a transaction three days ago
for over £50. 
To cut a long story short someone else didn't pay their bill mid week and for some reason they decided to put it through on my card, rather than whoever left their tab open. They have apologised and said they'll pay it back but I now have to wait potentially 10 days to get over £50's worth of my own money back! I don't understand how thy managed I do this on my card in the first place and think that this is really naughty- WWYD? Complain again to head office? Report them to someone else? Trash them on trip advisor?