peter.dubens AT pipex.net
mike.read AT pipex.net
try emailing them direct, these pair are the chief executive and managing director of pipex, also try
Sheena Shah <customercare AT pipex.net>
when l complained to mike and peter l had a reply from sheena within 5 or 6 hours and my problem resolved after 5 months of being ignored. I dont know if they send debt collectors etc because l am still with them and since l dont live on the uk mainland debt collectors arent legal over here, anyway, give the above a try, good luck :-)