The Scottish Ambulance Service has been accused of putting lives at risk by taking too long to respond to calls.
The Scottish Ambulance Service has apologised to the family
Agnes Alexander, a 77-year-old woman from Eyemouth in the Borders, is thought to have suffered a stroke after waiting more than three hours for help.
A Scottish Ambulance Service spokesman said the first call was non-emergency but admitted the ambulance had taken longer than an hour to arrive.
He said: "We have written in detail to the family and have apologised."
Mrs Alexander's husband Andrew said he called NHS 24 after she fell ill last November.
He claimed a nurse arrived two hours after his call and called a non-emergency ambulance.
However, Mr Alexander said she left before it arrived and as the pensioner's condition deteriorated her husband called 999 twice.
The family claimed an ambulance eventually arrived more than six hours after Mr Alexander called NHS 24 and more than three-and-a-half hours after an emergency ambulance was called.
He told BBC Radio's Good Morning Scotland programme: "The nurse had just left and my wife's condition deteriorated, she was violently sick - it was horrendous, I didn't have time to think about anything except keeping my wife alive and it was roughly about four o'clock in the morning before an ambulance arrived."
Christine Grahame, a Scottish National Party MSP for the area, said it was an increasingly common occurrence and has asked the ambulance service for a full explanation.
"For some time frontline crews have been contacting me raising concerns that Borders ambulance crews are being dispatched to Edinburgh to cover shortages in the city and that recent changes to rest periods for crews were leading to reduced cover in the region," she said.
"The experience which my constituents have faced demonstrates to me that current management of the ambulance service in the Scottish Borders is placing people at risk.
"The notion that it can take as much as three-and-a- half hours for an ambulance to arrive after an emergency call has been placed and six hours after the first call was made by Mr Alexander will frighten and horrify many Borderers."
Ms Grahame said the Scottish Ambulance Service management had conceded an error was made in allocating a nearby ambulance crew which had become available after finishing their rest period.
However, she said there remained serious questions about why it took so long for the emergency ambulance to arrive, the number of crews in the Borders and how they are deployed.
Mrs Alexander is understood to be recovering from her illness.