Desperate home buyers have been trapped for months in property purchase purgatory, leading to deals breaking down and people being left homeless.

Two weeks ago a “security incident” at the country’s biggest conveyancing firm, the Simplify Group, halted property exchanges and completions and put thousands of home sales in limbo.

But the nightmare began long before the cyber outage. Buyers and sellers using the firm have told Telegraph Money they wasted months chasing property lawyers for progress on their transactions, only to be ignored or given false promises.

Delays have been exacerbated by conveyancers losing important documents or repeatedly asking for details that had already been given. Property chains have been broken because of these hold-ups as vendors sought new buyers.

Industry insiders have partly attributed the problems to the sheer number of clients the company takes on, totalling hundreds of thousands each year.

Many clients are referred to Simplify by their estate agent; the majority who spoke to Telegraph Money had used ­Purplebricks. The online agent offers customers a “pay later with conveyancing” service, which allows payment of fees to be deferred until the property sells or 10 months after instruction.

But to qualify, customers must use Purplebricks’ choice of conveyancer – Simplify. 

For each client referred to Simplify and its brands, the estate agent receives commission. This is buried in its terms and conditions, but customers have argued they were unaware of this fact and felt duped by the deal.

One customer said she had asked to change conveyancer after the cyber outage at Simplify, but the request was denied by Purplebricks. Another home buyer claimed that the estate agent said switching would incur a fee of more than £300.

‘I have been ignored for seven months’

It should take around 12 weeks to complete a purchase. But Jenny Hubbard*, 73, who is moving from Shropshire to Cambridgeshire, has been left homeless after a seven-month ordeal involving Premier Property Lawyers (PPL), a subsidiary of Simplify.

At the beginning of November she moved out of her property to allow the buyers to complete before their mortgage offer expired. She claimed PPL assured her that her own purchase would complete in the same week. 

However, when completion failed to take place as promised she was left without a home and is now sharing a bedroom with her granddaughter and paying for storage for her belongings.

Her calls to the firm for an update went unanswered, or she was promised a return call that never arrived.

“The move was to be closer to my family and should have been a joyful occasion. Instead, in the final chapter of my life, I have been left homeless and in ill health from the stress,” she  said.

“In the entire seven months the conveyancer has not once contacted or returned the calls of the estate agent I am buying through. They are just hiding under their desks and I have been ignored from day one.”

Other customers of Simplify said they had been forced to move in with parents or sleep on sofas. One said she was likely to spend Christmas in a hostel with her one-year-old child after her chain collapsed following the cyber outage at the firm.

A Simplify spokesman said most of its systems were now back up and running. “We regret any uncertainty and disruption that our clients and others may have experienced over the past couple of weeks,” he said.

He added that more than 65,000 clients surveyed over the past two years had rated their satisfaction at nine out of 10. “The conveyancing industry has faced its busiest ever period due to the stamp duty holiday, with widespread delays across the sector,” he said.

He added that the company had reported itself to the Information Commissioner’s Office, the data watchdog which regulates potential breaches of personal details. 

A Purplebricks spokesman said: “Our model has always been that customers pay an upfront fee for our service, or they have the option of deferring it if they use our conveyancing service. We’re very clear on this with customers from valuations onwards.”