Jo Darbyshire bought her four-bed home in Bolton in 2010 from Taylor Wimpey without realising the full implications of the 999-year leasehold contract, which allowed the freeholder to double the £295 ground rent every 10 years. Only when a neighbour’s house sale fell through – because a mortgage company rejected the ground rent clause – did Darbyshire discover her home had been rendered potentially unsaleable.

When she inquired about buying the freehold, things went from bad to worse. Without her knowledge, Taylor Wimpey had sold the freehold to Adriatic Land at a price understood to be £7,375 for each of the 24 homes on the estate. Neighbours who have since tried to buy the freehold say they have been met with demands of £45,000-£50,000 – a huge amount compared to the £200,000 that some of the smaller homes on the estate currently fetch.

The ground rent company also demands £100 from householders who request a quote to buy the freehold. They also require that any householder wanting to make alterations – such as building a small extension – also pay a fee. “A neighbour wanted to build a small extension and was quoted £3,000 before a brick was laid,” says Darbyshire.

But Taylor Wimpey’s compensation offer has left her deeply frustrated. It offered a “deed of variation … specifically incorporating materially less expensive ground rent review terms”. It is understood the deal will involve the ground rent rising in line with inflation rather than doubling every decade.

Darbyshire says it still leaves her in the clutches of a ground rent company and what she alleges are its “exorbitant charges”. In an open letter to Taylor Wimpey chief executive, Peter Redfern, Darbyshire says: “You seem to believe the only wrongdoing is the introduction of doubling ground rents. The real scandal is the onward sale of ALL freeholds … to investment companies, and the consequences to us … Did you know that, once the freeholds were sold on, that Adriatic would introduce exorbitant charges for alterations and increase the cost of buying the freehold significantly?”

Darbyshire says Taylor Wimpey should be offering homebuyers the chance to buy the freehold at the price originally offered when the estate was built. Her letter adds: “The only acceptable way forwards is for you to reinstate me to the position I would have been in had your sales people, and the solicitor you recommend I use, informed me fully at the point of sale, when I would have purchased my freehold for £5,900.”

Darbyshire is not alone. Sean Greenwood, who Guardian Money featured last November when we first revealed the extent of the ground rent scandal, says the construction giant should refund the £101,000 cost of the apartment his wife bought in Gornal on the edge of Dudley. We highlighted how one apartment had received a “nil valuation” from a mortgage company because of the doubling ground rents.

Greenwood has also written to Redfern, saying: “My wife would still like a full refund. Unfortunately, your most recent offer to change the ground rent review to RPI is unacceptable. We are worried our freeholder maintains the position of power in all negotiations relating to our freehold.

“We are also not willing to wait for the time period it will take to complete the change in the deed. We have been trying to sell for over a year and a combination of the doubling ground rent lease and the collapse of the wall in our car park has meant we cannot sell.”

More than 4,000 people have joined a Facebook group, the National Leasehold Campaign, to protest over ground rent issues and excessive charges, with complaints directed not just at Taylor Wimpey but at other major developers, including Persimmon and Bellway.

Last week, Nationwide told the construction giants it would no longer offer mortgages on new-build properties with short leases or, crucially, where the ground rent is more than 0.1% of the value of the home.

In a statement, Redfern said: “This is about doing what we think is right. We recognise the concerns and difficulties that some of our customers have faced as a result of their doubling leases and we are sorry for the worry this has caused. Although we are under no legal obligation to take action, we want to help our customers.

“We are working hard with the freeholders to convert our customers’ doubling leases to ones that are significantly less expensive … and which resolve concerns around how easy it is to sell or get a mortgage. Taylor Wimpey will cover the cost of converting the leases.

“These leases were put in place between 2007 and 2011 at a time when economic conditions were very different. We stopped using them on sites commenced after 2011.”