The Warehouse has apologised after a barrage of complaints from customers who ordered items before lockdown.
Hundreds of customers weren't getting replies to their emails so they took to the company's Facebook page to air their frustrations.
The Warehouse admits it was caught off guard.
"There are a variety of things holding up deliveries but the primary culprit is unprecedented demand," said The Warehouse chief customer officer, Jonathan Waecker.
"The delays getting back to customers were significant and our customers bore the brunt of that because those delays were very real for them," said Mr Waecker.
But The Warehouse isn't the only big brand under the pump. Many are getting stock out the door, but it's getting held up in the postal system.
New Zealand Post says it's now cleared the backlog of parcels from Alert Level 3, with the vast majority now being delivered in two to three days.
Jill Brinsdon, co-founder of the brand agency Tricky, says Kiwi companies should be upfront with customers when things aren't going to plan.
"Crisis is a massive opportunity for a brand to demonstrate that it's trustworthy."
"Right now when there's a lot of stress in the system, when things aren't being delivered in time and there's no excuses that anyone can give that will make people feel better, the most powerful thing a brand can be in 2020 is human," says Ms Brinsdon.
The Warehouse is now promising to do better in the future.
"We absolutely want to do better, we are not happy with the level of service we're able to provide our customers at this point in time," said Mr Waecker.