If you take nothing else away from this article this a great point.
I once had an issue where two different electricity companies believed they were supplying our University flat. This turned out to be due to the mess of naming systems involved in Edinburgh flats where two apparently identical flats had meter numbers. Eventually I was able to extract this information from the call handlers but only after a ridiculous number of calls.
This got far better when I started taking names and extension numbers so that I could skip the intro session on each call and speak directly to someone who knew the situation. Taking careful notes of who I spoke to and when.
For about 2 years later I'd still get the hard sell from some debt collectors telling me that I could just pay the £2000 and it would all be over...