People are spending hours on hold while others are being disconnected as they try unsuccessfully to get through to Healthline for medical advice.
But the Ministry of Health says it is looking to bolster the service and has increased the number of staff to 150 since February to meet the increasing demand.
A Herald reader waited on hold to Healthline for three hours before hanging up and was frustrated that people experiencing symptoms could not get the advice they needed.
"It's ridiculous that I can't seek help or get clarification as to what I need to be doing if experiencing symptoms," she said.
Others who called Healthline received a pre-recorded voice message which apologised for not being able to take their call and advised them to call later.