The charges happened on June 15. I have been in the UK since May 17.
And now for the reason I am actually asking HN: Any idea what this could have been? Maybe a card skimmer? I bought fuel at Tesco and Shell (likely low-risk).
Obviously cancelled the card etc, but I have never been scammed like this and since this is so out of the blue I'm quite honestly a little dubious of Mercury Bank at this point.