this is who i used
http://www.drding.co.uk
he is just a 1 man, self employed person
he arrived early morning and he didn't leave until gone 8pm! didn't even stop for lunch, wouldnt get many people doing that i doubt
there were 3 dents he couldn't get access to, so couldn't do them unfortunately, ones near the edges of the door, so double skin just overlaps and nothing can really do, he removed wheel, arch liner, and drilled some holes behind there to gain access (then fitted a rubber grommet), he asked first and i said this was fine, i know someone people would object to this, but it is fairly common practice i believe, i guess you could remove the door cards before he came if you would rather no drilling, he can remove them, but obviously prices goes up, in the end, because i had so many dents, it cost about £8-10 each dent
normally he charges £70 first dent and £30 each one after, if you have more than say 5 then he does a deal