ring pipex on this number 0800 107 6443,give them some bull story,maybe play dumb,dont tell them who you are,and that your just enquiry about a tag on the line,which is there's,just ask them to check

Or maybe make out your a new customer,looking for broadband,they will check your line,and say its blocked ,

You can say,"oh dear,i didnt realise i had broadband,can you tell me who has the tag on the line please"
 

go here for more info about your line,and run a test,it will tell you exactly who has control over your line

 http://www.whatsmyip.org/more/

 GOOD Luck