Legal analysis:

If you owe 300,000 to a credit card and have not repaid it for 2 years, you should repay it as soon as possible. If it exceeds the prescribed limit or is overdrafted within the prescribed period, and the card-issuing bank still refuses to pay it back after being called upon by it, The behavior is suspected of malicious overdraft, constitutes the crime of credit card fraud, and will be subject to criminal penalties. If one party is sued by the court and refuses to perform after the court's judgment takes effect, the other party may apply to the People's Court for execution, or the judge may transfer the case to an executioner for execution.

Legal basis:

"Criminal Law of the People's Republic of China"

Article 196: Credit card fraud is committed under any of the following circumstances: If the amount is huge or there are other serious circumstances, the sentence is to be not less than five years but not more than 10 years of fixed-term imprisonment or criminal detention, and a fine of not less than 20,000 yuan but not more than 200,000 yuan; If the amount is particularly huge or there are other particularly serious circumstances, the sentence is to be not less than 10 years in prison or life imprisonment, and a fine of not less than 50,000 yuan but not more than 500,000 yuan, or property confiscation: (1) ) Using a forged credit card, or using a credit card fraudulently obtained with false identification; (2) Using an invalid credit card; (3) Pretending to use another person’s credit card; (4) Malicious overdraft. The term "malicious overdraft" as mentioned in the preceding paragraph refers to the cardholder's behavior of overdrafting beyond the prescribed limit or within the prescribed period for the purpose of illegal possession and failing to return the card after being called upon by the card-issuing bank. Anyone who steals a credit card and uses it shall be convicted and punished in accordance with the provisions of Article 264 of this Law.

"Civil Procedure Law of the People's Republic of China"

Article 236: Any legally effective civil judgment or ruling must be fulfilled by the parties concerned. If one party refuses to perform, the other party may apply to the People's Court for enforcement, or the judge may transfer the matter to an execution officer for enforcement. The parties concerned must perform the mediation agreement and other legal documents that should be executed by the People's Court. If one party refuses to perform, the other party may apply to the People's Court for enforcement.