Call Centre picks up then drops the call again immediately

Phoning the Natis Online Customer care number leads nowhere, you listen to the que "you are currently caller nr 6....." as you slowly progress to the next available person to speak with a representative, and then the line is picked up and dropped again immediately.. please look into calls that are picked up and dropped immediately (your Service Management can provide a report on this) its a common issue in call center's that by a certain time of day calls are no longer being picked up even if its still within advertised business hours. I have spent 2 x calls today waiting 30min on the first call and now 15min on the second call, I have been caller nr 3 with estimated hold times of 2min for the last 9 minutes