Tesco

I’ve got a home user customer here in the UK who used to use NTL dialup. The access number was prefixed with 1263. I have deleted all traces of NTL and Gearbox and installed Tesconet. The DUN still puts 1263 in front of the new access number when I use the Tesco dialler. I can’t find 1263 in the registry anywhere. If I set up a new DUN it doesn’t add the code but it won’t log on error 691). Any ideas?