Cryptopia is a great exchange one of the best of New Zealand. Until now they have never been known for any types of scams in the scams section. I have personally used the exchange but just traded something like 0.1 BTC. They have easy withdrawals and deposits until you remember the PIN code you have assigned which a type of 2fa of theirs. Moreover its the largest exchange with NZDT pairs. I see no problem with it so rest assured.