It's a shame we can't give 'zero' stars Castle Water are a nightmare, after moving me to monthly billing from 6 monthly billing without notifying me they keep adding late payment charges. I've wasted 4 months emailing to dispute the late payment charges on my account (which is in credit - but they estimate it and send incorrect bill). They add £50 to £120 at a whim, their online bills are impossible to understand, they are no better than scammers. They are now threatening disconnection and I am getting regular emails demanding money I don't owe. Their appears to be no way to escalate a complaint and they will not provide a deadlock letter. I'm forwarding my complaint to OFWAT. I would advise anybody who is with them to change supplier and anyone looking for business supply - do not use Castle Water.