Barmy billing?

[#1]

Right, I have closed my account with Plusnet and use Sky for broadband.  I have retained a free dial up account for my email.
So this afternoon, Plusnet have sent me two [2] identical emails telling me that I must complete my payment details so that my account is correctly dealt with!
If I completed any payment details it would not be correctly dealt with as I do not have any payments to make.  I am now convinced that the right hand does not know what the left hand is doing in their accounts department.  No wonder people are getting fed up with the billing.
My account details clearly state
"Next Payment This is a free account with no next invoice date"

[#2]

Had a phone call to say that the emails are generated automatically and they don't recognise free accounts.................. so I am to ignore them.

[#3]

Yeah, you can ignore them. Your account is free by default but can have chargeable components such as domains. As such, even PAYG accounts get standard billing / card expiry notifications.