A retired couple who received a number of huge water bills have been told they have been paying for their neighbours' water as well.
Ted and Doreen Howarth have received bills totalling £4,400 since a meter was installed at their home in Styvechale, Coventry, in 2002.
Following an investigation into the case, they have now been told by Severn Trent Water that they have been paying for water for between three and five other houses in Leaf Lane after the meter was put on a pipe leading to all the properties.
Mrs Howarth, aged 73, a retired secretary, said: "It is absolutely disgraceful.
"We have always known something has been wrong. It's been a nightmare for over three years.
"Every time I opened a bill I nearly had a heart attack and it ruined the rest of my day."
A new meter has now been installed in the Howarths' bathroom to ensure they are only paying for their own water.
It is unclear how much extra money they paid to Severn Trent Water but it will now be calculated based on the readings for the new meter.
Neighbours had still been paying for their water so did not notice anything unusual about their bills.
Mrs Howarth said: "We have been trying to sort this problem out for over three years and the problem was d iscovered within five minutes.
"For every £10 our neighbours have been paying we have been paying about £50," she said.
The couple were delighted after they had a water meter installed at their bungalow in 2002.
When bills were based on rateable value, the couple paid about £300 a year. But, in the first year of metering, their bill plummeted to around £120.
However, their joy was shortlived because over the next three years Severn Trent sent demands totalling nearly £4,500 - despite the couple paying a monthly amount fixed by Severn Trent.
Mrs Howarth said: "We have always been very careful with water. We had the meter installed because my husband and I live alone and we thought a metered supply would be cheaper.
"The bills themselves are incomprehensible. We have been treated as an account number and not as people. I wish we had never had the meter installed."
Severn Trent admitted there had been a mistake and the meter should not have been fitted on a pipe supplying more than one house.
A spokesman for the water company said: "We apologise to Mr and Mrs Howarth for the problems they have incurred.
"The amount of water on their bills was high but not impossible for a domestic property.
"The meter should never have been installed where it was."
Mr and Mrs Howarth will be reimbursed for the extra money they paid on their bills but it is unknown if they will receive compensation for the stress caused.
Mr Howarth, aged 74, a retired engineer said: "We have been extremely upset by all the problems caused by Severn Trent Water.
"But at least the nightmare looks like it might be over."