As a member of staff I am entitled to a discounted monthly subscription to BT Yahoo's services. My experience was like most people here have described with busy tone on my dial up access and being unable to contact customer services and technical support going to a 50p a minute number, (for f*** sake I only wanted to report yet another problem). In the end I ceased using their services and had to threaten them with the County Court to get back the money I had paid them for the time I could not use the service.
I have now decided to pay more and have broadband from a proper ISP. At least this way if there is a problem with my wholesale ADSL line my ISP will be able to make a complaint to Offcom to get things sorted out.