Hi there! I understand you're getting an error when trying to authorize a transaction in the Exxon Mobil Rewards+ app, and you've already confirmed that your card number is correct. Let's work through some checks to get this sorted out.

First, a couple of quick questions to better understand the situation:
- Are you trying to pay at the pump or inside the convenience store?
- Is your location (GPS) service turned on and has the app permission to access it?
- Have you checked if the app is updated to the latest version on your Android device?

Sometimes, authorization errors happen because the app needs location access to verify the transaction or because the app version is outdated.

Here’s a step-by-step solution to try:

1. Enable Location Services:
Go to your Android settings > Location, and make sure location is turned on. Then, under apps, ensure Exxon Mobil Rewards+ is allowed to access your location.

2. Update the App:
Open the Google Play Store, search for Exxon Mobil Rewards+, and see if there’s an update available. Updating can fix many bugs including payment issues.

3. Clear Cache and Data of the App:
- Go to Settings > Apps > Exxon Mobil Rewards+
- Tap on Storage
- Select Clear Cache and then Clear Data (this will not delete your account but may log you out)

4. Log Back into Your Account:
After clearing data, open the app, log in again, and try authorizing the transaction.

5. Check Your Payment Method:
Beyond the card number, verify expiration date, billing address, and any security details are correctly entered in the app’s payment settings.

6. Try Authorizing Again:
Attempt the transaction once more.

If you’ve done these already, please let me know which steps you’ve tried. Also, if you’re seeing a specific error message, sharing the exact wording would help me assist you better.

If the problem persists after these steps, there could be a temporary server issue or something specific to your account that might need direct assistance from Exxon Mobil Rewards+ support.

Would you like me to guide you on contacting support via email or phone if needed? The customer service email is [email protected], and phone support is available as well.

Let me know how it goes! Are you satisfied with the solution I provided?