They seem to have continuous turmoil through restructuring, going back to their initial formation.
This year I talked to a head hunter, who mentioned a Spark position. Here's my reaction.

Anyhow from Stuff from Tom Pullar-Strecker
https://www.stuff.co.nz/business/industries/104703350/spark-gives-staff-a-week-to-consider-new-job-contracts
"Spark staff get 5 days to consider new job contracts - not long enough, says expert"
New employment contracts are part of a wider rolling restructure at Spark that will see several hundred staff leave over an 18-month period.
"About 1900 Spark staff are being given five days to sign new employment contracts agreeing to new ways of working, or leave the company.
But employment law expert Max Whitehead said the staff appeared to have been given too little time to consider their options.
He believed they might be able to argue their old jobs still existed and they could not be forced out the door.
The new contracts have been prompted by Spark deciding last month to bring forward part of a wider structuring programme that is expected to see several hundred staff leave the company between June last year and this December."