Have a customer that has been using my app for a while, the subscription has expired and when I have them go into settings on their iPhone, and click their name, and then subscriptions, it shows their payment method was declined. They have tried different cards and have already contacted Apple support, which tells them it is my app. They use my app for production and are down currently, need help.
How can it be my app when it shows that they need to "Update Payment Method" in their subscriptions?
See photo attached of what they see.
Thanks!