Today I called Cymru Water because we have a £300 credit on our bill (we pay £50 a month direct debit) and wanted to adjust our direct debit since we had such a large credit. The rep immediately said our meter must be slowing down since we have 7 people in our house and were apparently using too little water for that many people. (possibly correct) So they are going to replace the water meter. Oops, darn, but oh well. Our problem is this: They say that once the new meter is installed, they will check the readings every few weeks and then use these numbers to 'correct' our past bill (up to 7 years). We are arguing over this because we do not feel they should be able to guess what our usage was for the past year or two and make us pay for their meter possibly slowing down. They have no way of going back in time and knowing exactly how much water was used. It was their mistake and while we have no problem ensuring that we pay what we use from now on, we are angry that the company can just say 'we think you used this much water while your meter was slowing down so give us the money.' And since we have a £300 credit, they will take it from that. The rep said they would generally not make a customer go negative on their bill. I asked for a refund of our credit then and they do not appear to plan on giving it to us. Can Cymru Water back bill us on guesstimate of water usage and not an accurate reading of the meter?