After the phone call, you can usually find the result the next day.
Credit card application is comprehensively evaluated by the system, and there are many reference factors, such as work, income, stability, personal credit, etc., which are not determined by unilateral factors. Perhaps the information attached to your application did not fully show your personal situation, which led to the failure of your application.
Because the credit standard and scoring standard are confidential within the bank, the risk-related factors cannot be announced to the public, which you can understand. You can call 400-820-5555 to request re-inspection. I hope you can provide us with more reference materials. If you don't want to attach more information at present, you can reapply 3 months after the first application.