Labour says an 0800 call centre number which replaced many Housing New Zealand offices cost almost $300,000 in April - the first month since the change.
Labour says by its calculations, calls to the 0800 number cost 20 cents per minute.
Housing spokesperson Annette King, says 119,694 calls were made to the number in April, and 53,054 unanswered.
She says unanswered calls have cost $92,855,50.
Housing Minister Phil Heatley says the problems are an operational issue.
He says Housing New Zealand has addressed some technology problems and put more staff into the call centre.