Went to Duo in London today on the strength of these recommendations. Completely rammed (MNers?) and the famed fabulous service was shite. (Is it me?) Also the £20 off everything code had just finished last week , though there is free delivery at the mo.
I did find a lovely pair of boots which actually fit, and which I'll use to walk a couple of miles a day to and from the childminders. But I can also wear them in the office hopefully too. So they are probably a bit smarter than what OP wants but still worth mentioning.
lovely boots - the ankle strap is detatchable
This is a total revelation after trekking round Dune, Hobbs, LK Bennett etc. trying on boots which gape so much they look like wellies on me.
I would say that Dune also had some decent boots and so if you are lucky and they fit you, then might be good.
more lovely boots - more casual