More than a third of people who move house are experiencing delays in the set-up of their broadband, a consumer group has found.
Citizens Advice found that people moving into a new home were "often" left without a working internet connection for weeks after the set-up date given by their provider.
Others reported having to wait at home for engineers on multiple occasions or being left with a slow or intermittent connection.
The advisory charity found 15% of house movers with a broadband connection found it was slow or unreliable when initiated, 11% reported that engineers had to make multiple visits and 9% had their engineer appointments rescheduled.
Among the cases reported to the charity, one woman did not have a broadband connection for three weeks even though she had paid £82 upfront for the installation and first month of fibre, and had called her provider repeatedly about the problem.
When she asked to cancel the contract she was told that as the 14 day cancellation period had passed she would have to pay an exit fee of more than £200.
The findings come after last month's launch of the Government's £400 million Digital Infrastructure Investment Fund to boost investment in "full-fibre" broadband that can offer speeds of up to 1Gbps to households and businesses.
Citizens Advice is calling on regulator Ofcom to put in place the mandatory scheme it proposed earlier this year for automatically compensating people affected by delayed set ups or repairs to their broadband or landline.
Citizens Advice chief executive Gillian Guy said: "It is fundamentally unfair that in some cases customers are paying for a service they don't receive for weeks or even months at a time after moving.
"Ofcom has rightly proposed a scheme that would automatically compensate customers who face delays or missed appointments, regardless of their provider - but this is now at risk of being watered down by a rival industry proposal that would be voluntary and lower the amount paid out by at least £52 million.
"To hold providers to account for breaking promises to their customers, the regulator should move forward with its mandatory automatic compensation scheme.
"This would make it clear to people what they are entitled to when they get poor service and put an end to customers having to negotiate how much they get back for their wasted time."
People sought Citizens Advice help with 7,500 problems with their internet service providers and 3,500 problems with landline telephone services in the year to June.
It said previous analysis of 1,000 cases reported to the service between August 2016 and May 2017 indicated that 18% of those with broadband problems would be eligible to receive a payment under Ofcom's proposed scheme.
* YouGov surveyed 2,009 UK adults online between March 6 and 15.