Why are you invoicing me?

Why are tou invoicing me if I am not a client. I put through an application for a 20/10 line went through all the hoops only yo be told by a call centre staff that that line is not available to me so I cancelled but now I have a 60 days arrears invoice from you. What in the actual f@&?, you are the worst company in the world that don't have a clue what you are doing. Please remove this from my name as this will affect my credit score... you have no right to do this to anyone, why in the hell. This is utterly unacceptable!