Apple

So I repeatedly got notification to update my payment method on my iPhone. I do have credit balance on my phone but for some reason my phone is redirecting me to add more credit balance. When I go to payment method it tells me to update my billing information but all the billing information are correct. Been in this loop since yesterday. I have previously set my mobile number as Payment method on my iPhone and I am often using to purchase in game credits from Apple store. Until yesterday when this issue started.

Model is 12ProMax for reference.

Can someone guide me on how to fix this issue? Am I missing something ?