I'm not 100% certain, but I doubt anyone from NTL would do it.
Might be best off heading to a local independent TV/Video shop (if there is one nearby) or looking in yellow pages for a TV repair man. You'll probably be looking at £50 minimum.
To summarise the connections, you need 1 x Scart cable from NTL STB to TV, 1 x Scart from DVD to TV and 1 x Scart from STB to DVD. In addition you will need standard aerial cables from STB to DVD and DVD to TV.
HTH