Mitre 10 MEGA Manukau is a hardware store at 61 Lambie Dr, listed under Stanley Brook, Tasman, with a Google rating of 4.3. Mitre 10 MEGA is a large New Zealand hardware and garden chain. The name and listed locality point to different places, so it is worth confirming the address before you visit.
A good hardware store helps you finish a job properly: staff who ask what you are doing and suggest the right fixing, paint, tool or material, not just the nearest one. Bring a photo, measurements or the old part, and ask about alternatives if a product is out of stock. Regulars buy a little extra of screws, sandpaper or fixings, ask about tool hire for one-off jobs and check what is needed before starting, since a missing piece can mean a second trip. For electrical, gas or structural work, remember that in New Zealand much of it must be done by a registered tradesperson, and staff can advise what is safe for home use. Early weekday mornings are often quietest.
For DIYers around the Tasman area, this is a well-rated listing to check for hardware and garden supplies.