"We are sorry for that. It is not a situation we want to be in. We are committed to working co-operatively with the Bay of Plenty Regional Council to address these issues as quickly as possible and deliver reliable public transport."
She said the driver shortage was a national issue the company also experienced in its Auckland and Wellington operations.
The company paid Bay drivers $2 an hour more than the previous contractor but faced recruitment competition from other companies and transport industries, and had difficulty hiring over Christmas in a tight labour market.
Of the 150 full-time equivalent drivers needed, they had 110 and another 6-10 expected to start training - which takes up to 10 weeks depending on experience - soon. She estimated it would take 10-12 weeks to hire another 30 drivers.
The shortage issues were exacerbated by the return of schools and the increased scope - particularly in weekend work, which came with additional rostering complications - of the new service.
Riled-up councillors said the company either knew about or could have predicted those challenges when it tendered for and signed the contract.
Neville said the company tendered in 2017 when the shortage was less severe and started recruitment six months ahead of the launch.
NZ Bus was leaving "no stone unturned" in its effort to find drivers, including talking to other operators, recruiting internationally and lobbying the Government to have driving put on the skill shortage list.
Some of the harshest criticism came from regional councillor Kevin Winters.
"All I have heard this morning is excuses. You signed a contract, you have to deliver.
He said he regretted not doing more due diligence before voting to award the company the contract.
"You are single-handedly letting us down big time by your non-performance."
He said the driver shortage situation was "just bizarre".
He was among several councillors said they would not accept a proposal to reduce the advertised level of service until the driver shortage was resolved.
At the start of the meeting chairman Lyall Thurston issued a personal apology for the impact the issues had on bus users.