Okay, no need to guess because I'll tell you......... Fly London Boots. . I saw the original thread about the £40 offer on the Office website but I didn't like the boots when I saw the picture.
I went to Office today and absolutely loved the boots so now I have a pair. Yippee. I have literally lived in Converse for the last 5 years so it's fantastic to have something smarter. Thank you Mumsnetters for drawing my attention to them.