The bank will not promise you to handle the limit increase business through telephone marketing, so it must be fake.

CCB’s credit card limit increase is evaluated by the system and comprehensively determined based on your consumption and repayment status.

If you need to adjust the limit, you can call customer service, and the customer service will help you check whether the limit can be adjusted based on your current situation (that is, check the system evaluation results). In addition, you can also log in to the official APP software of China Construction Bank "China Construction Bank". After logging in, scroll down on the credit card function page to find "Limit Adjustment" and click to enter. You can check whether your current qualifications can increase your credit limit.