This link is a good article we found around complaints and feedback from the citizens advice bureau.
Although there are marked differences in the ratios here, in particular with regard to Scottish Power, it is good to see that the likelihood of you having to raise a complaint is actually quite low.
Scottish Power have been struggling, following the introduction of a new computer system – which is always a challenging time for any company. What’s pleasing is that they have taken steps to improve things. This is a situation that we are monitoring.