Hello QA_Thunder,
Thanks for visiting Apple Support Communities. We understand that you're having an issue downloading an app as you're continually being asked to verify your payment method. If you haven't already, restart your iPhone, then try again. Restarting can resolve many odd issues: Restart your iPhone
If the issue continues, see if these steps help: If you can't connect to the App Store, iTunes Store, or other Apple services
If you're still having trouble, complete the following steps, testing after each one:
- If possible, test while using a Wi-Fi network instead of cellular data only
- If you're using a VPN or security software, temporarily disable or remove those as they can sometimes block connection to servers. If that helps, work with the app developers more: How to contact an app developer
- Reset your network settings. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you’ve used before. Be sure you have your passwords handy before resetting. When you're ready, tap Settings > General > Reset > Reset Network Settings.
Keep us posted on the results.
Take care.