I'm not sure whether you should take the risk with BTCC or not. Although they are a professional bitcoin exchange and one of the biggest in China in terms of trading volume and user base you should always be careful dealing with foreign companies.
Laws may vary from country to country and it would be very hard for you to dispute something if BTCC did froze your account balance.
OP only ask about justpay wallet
not about trading in bttc
i think justpay same another wallet not need verified, same blockchain, only send and receive bitcoin
so only bitcoin wallet is nothing about frozen
about justpay wallet
https://pay.btcc.com/walletif about frozen wallet maybe send bitcoin still not confirmation so still frozen