WhatsApp bans millions of accounts every month. If you want to save your account from getting banned then don't do these mistakes. Sending messages or sharing numbers from unknown numbers without consent.
Creating fake accounts or chatting falsely under someone else's name. Using personal information of others without permission. Bulk message, auto-message or auto-dial using WhatsApp.
Repeated use of broadcast messages as reported by other users. Creating accounts or groups through unauthorized or automated means. Using third-party WhatsApp apps like GB WhatsApp and WhatsApp Plus. Sharing files that may contain viruses or malware.
(pc amarujala)