Hi! I understand you're having trouble with the MSC app not accepting your billing information. To help you better, could you please clarify a few details for me?

1. Are you trying to add a credit/debit card, or another payment method?
2. Does the app give any specific error message when you enter the billing details?
3. Have you tried entering the information multiple times or using a different card?
4. Are you attempting this on the MSC For Me app or through a website on your Windows device's browser?

Once I have a bit more info, I can guide you through steps to resolve this smoothly. Meanwhile, here are some standard fixes that often help with billing info issues in apps like this:

1. Check your card details carefully: Make sure your name, card number, expiration date, and CVV are entered exactly as they appear on the card—no extra spaces or typos.
2. Update the app: Ensure your MSC app is updated to the latest version, as older versions can have bugs affecting payment processing.
3. Clear app cache (if possible): Though Windows with WebKit might not have a standard app cache, try clearing your browser cache and cookies if using the browser form.
4. Try a different payment method: If one card isn’t accepted, try another if available. Some users have reported success switching card types (e.g., from Visa to Mastercard).
5. Use a different browser or device: Sometimes the app or website behaves differently across platforms, so testing on another device or browser may help.

If these don't resolve it, sometimes the MSC app may temporarily have glitches with certain payments. There are reports users couldn't add cards but were able to finalize payments onboard or via kiosks after a day or two1 3.

Could you please provide more about the error or your attempts, and then I can suggest more specific next steps?