I want update my payment via mobile number,but unfortunately there is some problem

If you use mobile phone billing as an Apple ID payment method, see this Apple article: If there's an issue when you set up mobile phone billing -> If there's an issue when you set up mobile phone billing - Apple Support (MD)

You need to add funds to you SIM card balance, or provide a new payment method.

See ⤵️

Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

Add a payment method to your Apple ID

Add a payment method to your Apple ID – Apple Support (UK)

Add money to your Apple Account balance

Add money to your Apple Account balance - Apple Support

I have already balance in my mobile number

Have you contact your carrier?