By the looks of things it seems as if Cryptopia is going under....fast...Everyone is missing deposits, support is non-existent. Yet, from the looks of their social media everything seems to be running fine, hell, they're even adding new coins! (of which you lose your deposit when you send it). No word from support on any public platform about the massive amount of people missing funds for weeks. Honestly, it's feeling like Cryptopia went from decent to a complete scam overnight.
I am a user of cryptopia and for me the exchange do not have any issue. My brothers and my friends are also using it from a longer time and we often trade on that exchange for electroneum and it goes nice and smooth without any issue.
I do not know that why you have that much complaints with that exchange. You make sure that you follow all of their guidelines. If you will read the terms and conditions of rules of any platform you want to join before registration and then follow them then you will not face any issue on there.