Severn Trent Water finally settled the outstanding case of my account that's been dragging on since I moved in in March. There was a significant leak by the meter - out in the footway, thankfully, which they fixed.
They took a meter reading in August post-repair and recently, so instead of £580, it turns out I've used about £70-worth since March. Luckily, I'd dug my heels in in April and refused to up my direct debit until they investigated.
I'll be getting a refund of the small overpayment and a £25 goodwill payment for them being twunts.