You've hit on a real beauty problem here. Unlike State-side nail bars that re cheap, quick and effective, we make more of a fuss about mani's and pedi's. While there are many high st chains that offer a file and re-shape (think of Nails Inc and the New York Nail Company) you won't get the kind of nail-fix you are used to. Again, not cheap, but undoubtedly the best over here, hun out a Leighton Denny-trained nail technician (find your nearest on leightondenny.com). Having trained in Florida he really 'gets' what is needed and demanded by the most discerning of manicure clients. Expect to pay upwards of £30