A 74-year-old man with heart problems collapsed on a Dunedin golf course and was told it could be up to three hours until an ambulance reached him.
David Cameron, of Dunedin, said he was at Island Park Golf Club in Waldronville when he felt lethargic and had a dizzy spell, falling from the trundler where he had been sitting.
Witnesses called 111, but ultimately took him to Dunedin Hospital themselves.
St John has now apologised, saying all available ambulances were tied up when Cameron lost consciousness about 2pm last Wednesday.
Cameron said it was fortunate he had friends and his brother on hand.
Cameron said he believed St John was not to blame but a lack of funding was.
His son, Paul Cameron, also of Dunedin, said he was concerned as his father did not like to complain but had a history of heart problems, including a heart attack just 18 months ago.
His father lost consciousness twice between when St John was called and his arrival at the emergency department.
The waiting times were astounding, and he could not understand how the service was not fully funded, he said.
He believed the ambulance system needed an overhaul as the pressure would only get worse when winter hit.
As a father himself, one of his worst fears was calling for help for one of his children and no one showing up, he said.
St John coastal Otago area operations manager Doug Third said because of the widespread community outbreak of Covid-19 the ambulance service was experiencing the highest number of calls in its history.
Cameron's condition was coded as serious but not immediately life-threatening, so the caller was asked to arrange private transportation if possible and call back if the condition worsened.
St John was sorry that its service fell below expectations and encouraged Cameron to get in touch directly if he was unhappy with his care.
The service was grateful for extra pandemic-related funding it had received from the Government and was hopeful the current round of talks with funders regarding a new four-year emergency services contract would provide long-term sustainability, he said.