The Welsh Ambulance Service has apologised to a 91-year-old cancer patient who waited nearly five hours to be taken to hospital.
Harold Griffiths' family say the ordeal left him "distressed"
The family of Harold Griffiths, from Caerphilly, said they have lost confidence in how the service is run.
Doctors wanted him taken as an urgent case to the Royal Gwent Hospital, Newport, when his health deteriorated.
Ambulance officials said a high number of 999 calls on the day was to blame for the delay.
The pensioner's family said he grew increasingly distressed as he was left waiting at home to be taken to hospital.
The decision to admit him followed a visit by the family's GP who asked for Mr Griffiths to be treated as an urgent case.
His son Gwyn Griffiths said they expected to wait an hour, but after three hours had passed there was still no sign of an ambulance.
"It was frustrating for my father since he knew at half-past 12 he was going to hospital, and yet he was lying in bed thinking 'when is the ambulance coming?'," explained Mr Griffiths.
"He was getting more agitated, more distressed and because of that he was getting more breathless and his heartbeat was increasing."
After frantic phone calls and another wait of nearly two hours, Mr Griffiths was finally taken to hospital, where he had to be given emergency treatment.
His son said he had nothing but admiration for the frontline ambulance drivers and paramedics, but added: "I have no respect for the managers who are, so they say, restructuring the service.
"To me that smells of cutting down on services."
The ambulance trust said a high volume of emergency calls at the time were responsible for the delay in getting to Mr Griffiths.
Chris Simms, the regional director for the service in south east Wales, said both the ambulance crews and hospitals are under immense pressure at this time of the year.
"The care system itself over the last three months has been under increased pressure," said Mr Simms.
"Both ourselves and the hospital trusts have seen an increase in the amount of admissions of patients going into hospital.
"As a result of that it does give problems trying to cope with that demand.
"If it was spread reasonably throughout the day it would be fairly easy to achieve, but it tends to come in peaks, and that's when the blockages tend to crop up in the system."
The ambulance service has apologised to Mr Griffiths and his family, and said it was also introducing changes that would see "high-dependency" vehicles.
It is hoped that these ambulance teams will be able to deal with cases like Mr Griffiths in the future, rather than relying on emergency 999 crews to take patients to hospital.
A spokesperson for the Welsh Ambulance Services NHS Trust said: "We are extremely sorry that we were not able to provide Mr Griffiths with the timely care he needed.
"This was because of the high emergency demand in the area at the time with all available crews committed to emergencies."