At the time of December month, maybe if I'm not mistaken around the date of 11/12 December cryptopia had an error on their wallet, so the deposit of the users did not enter.
But after a day they can fix the problem, and apologize to the users.
Well, naturally if an exchange has an error because of the many community interest that started a lot to switch to crypto trading.
cryptopia is a good exchange place, maybe you should wait for a while so your deposit will appear.