When you are overdue for a long time and ignore the bank's dunning notice, your credit card account will be frozen by the issuing bank. It will affect your personal credit record and you will not be able to apply for a housing mortgage loan normally in the future.
What is more serious is that if the amount owed is large and overdue for a long time, it may even violate the criminal law. According to the relevant regulations, if the cardholder overdraws beyond the prescribed limit or time limit for the purpose of illegal possession, and fails to return it for more than 3 months after being urged twice by the issuing bank, it shall be deemed as "malicious overdraft" as stipulated in Article 196 of the Criminal Law.