I too am surprised that CISAS acted without a letter of deadlock.

The first port of call should be ISPA. My own case and several others have been resolved this way without escalation.

You first send an email or letter titled Official Complaint to Pipex Customer Care (now renamed Customer Relations I believe). State in it that this is a final effort at resolving your problem before invoking an ISPA compaint. Pipex have 10 WORKING days to respond. If you don't get a satisfactory reply, you fill in an online complaint on the ISPA website. (Keep a copy of what you say because ISPA don't archive it and you will need to repeat it if a 2nd visit is necessary. They contact the ISPA rep nominated by Pipex with instructions that they must contact you to resolve the problem within 5 WORKING days. If it is not resolved you go back to ISPA and they will instruct Pipex to give you a reference number acknowledging deadlock so it can go to CISAS.

Explanation of ISPA Complaints procedure: http://www.ispa.org.uk/complaints/page_40.html

Online Complaints Form: http://www.ispa.org.uk/cgi-bin/complaints.cgi