I think there's a much deeper problem at Scottish Power than just IT systems. I spent close to a year trying to get them to fix an incorrect bill and nobody I talked to had any idea what to do (probably 6 or 7 people across various departments).
I know many others who have had similar problems with Scottish Power, and I'm sure there will be more testimonies in other comments.
The question on my mind is how does a company resolve such deep-rooted institutional failings?