This is brilliant - 2 months ago I cancelled my broadband account. I noticed last week that since then 2 payments had been taken by direct debit (should have cancelled that too and checked, I know!) so I logged in here and raised a second cancellation.
PN responded to say they had no record of my first cancellation (useful) and that I owed them £49 odd for a previous house move and £19 odd for the past month. I told them that as I had paid for 2 months of account which I had not used having cancelled it they could whistle and confirmed that I did not authorise any further payments.
This morning I have received an email telling me they have taken £21.49 using my debit card. This is nothing short of theft!