Water bill boycotters have labelled complaints processes in the industry “a sham” and not fit for purpose as they protest against firms’ handling of waste water disposal.

In an open letter to Environment Secretary Therese Coffey, around 50 customers from seven water companies across England and Wales said they have no effective way of challenging firms about not getting the service for which they are meant to be paying.

The group described their experience of dealing with redress bodies after they complained to water companies about failing to dispose responsibly of waste water during specific bill periods.

Customers have been withholding payment for part of their bills from 10 of the 11 water companies providing sewage treatment services in England and Wales, according to Katy Colley and Julie Wassmer from the boycottwaterbills.com campaign.

Toothless regulation has allowed water companies to routinely abuse their monopoly positions by providing an inadequate level of service

In the letter, they claim that once their complaints have been “unilaterally dismissed” by the water companies, they are advised to go to the Consumer Council for Water (CCW), a public body sponsored by Defra which describes itself as “the voice of water consumers”.

But the group said the CCW routinely responds that they are unable to deal with their complaints on sewage discharges.

In one email attached to the letter, a CCW caseworker tells a customer that the next course of action would be to contact their local authority and the Environment Agency as well as the Water Redress Scheme.

The letter says that the Water Redress Scheme (WATRS) told one customer their dispute would be “better suited to a court or the regulator in the water sector”.

The group wrote: “Not one of the bodies mentioned above is apparently empowered to act in our interests. The system is not fit for purpose.

“Toothless regulation has allowed water companies to routinely abuse their monopoly positions by providing an inadequate level of service, thus undermining the rationale for a regulated monopoly.”

Ms Colley, from the group Hastings Boycotts Southern Water, says: “We have been sold a lie – that if we are good customers and go through the proper channels, we will be listened to and taken seriously.

“Nothing could be further from the truth. The advice we have received is contradictory, absurd and designed to put off a customer from complaining in the first place.”

Ms Colley and Ms Wassmer said the website has attracted thousands of visitors since it was launched in June.

Meanwhile, groups from Lewes and Yorkshire have joined the call for people to boycott water bills in protest at persistent sewage dumping.

“It feels like a sea change is taking place over what people are willing to do,” said Ms Colley.

England’s privatised water system is circling the drain. Decades of prioritising dividends over investment have left our sewers leaking and a debt mountain fifty billion pounds high

Matthew Topham, lead campaigner at public service campaign group We Own It, also called for England’s water systems to be nationalised.

He said: “Westminster must listen to the anger in the letter today.

“They have the power to bring water into public hands. It’s time to pull the plug on a system that has been a get-rich-quick scheme for overseas governments and shareholders. Now they must act.

“England’s privatised water system is circling the drain. Decades of prioritising dividends over investment have left our sewers leaking and a debt mountain fifty billion pounds high.

“Trying to suppress the worst impulses of profit-hungry water companies has failed. Regulators are caught in an impossible bind between shareholders and the public.”

A spokesman for the CCW said: “Our advice to customers is always tailored to the individual circumstances and in these instances it appears different scenarios have been presented to us.”

They added: “Where a customer withholds payment as part of a protest around overall performance of a water company we would not recommend this course of action as it can have serious consequences for a customer’s finances.

“Their credit rating could be affected and they could be taken to court.

“CCW’s role is to help people resolve their individual customer service complaints against water companies.

“Any issues people want to raise about the general performance standards of water companies is a matter for Ofwat.

“Matters relating to the protection of our rivers and seas is the responsibility of the Environment Agency or Natural Resources Wales.

“CCW supports around 13,000 customers every year with complaints and enquiries and last year secured nearly £1 million in financial redress for households and businesses.”

PA has contacted the Department for Environment, Food and Rural Affairs and WATRS for comment.