T-Mart Refuse to pay return shipping on defective goods Internet

I ordered, and duly received a TV wall mount from TMart. On opening the box I was suspicious because it did not look factory-packed. OK, not a problem. Then a screw fell out of the box. Unusual. Then I noticed that the dry-wall plugs had plaster on them. OK this was a returned item. Not necessarily a problem.

Looking at the instructions I found that the wall mount had been partially disassembled by the previous purchaser. It appeared obvious how to put it back together, but then I realised that it would be loose and wobble. Not good for a TV mount.

So I asked TMart to either send instructions for reassembly, or for a replacement item. They asked for photographs. Duly supplied. Then they asked for it to be sent back. Rather silly for such a large and heavy item when it only needed some instructions. They also stipulated that return shipping could only amount to 30% of the value. The cheapest shipping with NZ Post was $100. With a local parcel shipping company it was $130. Not good for an item priced at $140.

I reported shipping prices to them and they simply repeated the demand for it to be returned but they would only pay 30% (less than half of the shipping costs). Several repeats later the same words keep coming from them. Their latest message is:

Dear Valued Customer, 

Thanks for your email, it is our honor to help you.

Sorry, this is our fault, but we need your help to return it to us, since the item is expensive. Hope you can understand.
As for your issue, could you please use the cheapest shipping way to return it to us?

Please use the cheapest shipping way which is no tracking number.

And we can only refund you NZD45.09 as the compensation of the shipping fee. Do you accept or not?

After we receive the returned item, we can reship a new one for you and refund you the shipping fee according to our policy.

Hope you can understand.

So they need 'my help' (meaning my money) to pay for their mistake. No I do not understand. I still do not accept their refund offer.

I recommend only buying small junk items from them in small quantities (you get free shipping after all) so that you can afford to discard any faulty items. Get anything you really want from a reputable retailer. Otherwise be prepared to lose your money.

Howard, Nelson New Zealand.