Hi there! I understand you're having trouble purchasing diamonds in Fishdom. To help you better, could you please tell me:
- Are you getting any specific error messages when you try to buy diamonds?
- Which payment method are you using?
- Have you been able to make purchases before on this device or is this your first time?

Meanwhile, I can guide you through some common steps to try:

1. Restart your device and then try the purchase again. Sometimes the store might be overloaded or temporarily unable to process requests, so this often helps.
2. Ensure your Fishdom app is updated to the latest version if you are using the app. On Windows and WebKit, refreshing or clearing your browser cache could help too.
3. Double-check your payment method details to make sure they are current and valid. Sometimes, payment verification issues can block purchases.
4. If you’re using an account linked to stores like Amazon or Google Play, try re-verifying your payment method there.

If you’ve tried these or have additional info, let me know so we can dig a little deeper!

Are you satisfied with this starting set of suggestions?