The Warehouse - which used to be considered a relatively good employer for a retail operation - is trying to force its staff to work 10-hour days and 50-hour weeks, with no consultation on changes and no accommodations for personal circumstances. The net effect will be to make personal life pretty much impossible for its workers. A ten hour day leaves little time for anything other than working, eating, and sleeping, while it is impossible to plan anything when your shift may be extended by two or three hours with no notice whatsoever.
Back in 1840, Samuel Parnell established the eight hour day in New Zealand by the simple expedient of refusing to work for longer. He must be spinning in his grave right now. People didn't fight for the eight-hour day back then just so we could be returned to Victorian working conditions today.
Unfortunately, with National in power we can't look to the government to do anything about this (hell, they want to steal people's meal and rest breaks, another step back to the 19th century). If we want an eight hour day, we'll have to fight for it ourselves. Back in Parnell's day, it was enforced through violence - those working longer than eight hours were dunked in Wellington harbour. That's wrong, and it punishes the wrong people (the workers rather than the bosses who are forcing them to give up their lives) - but we can refuse to shop there. So, my advice is don't shop at the warehouse this christmas. Spend your dollars somewhere which allows its workers a life instead.
