There are several possible reasons to why a debit/credit card deposit is not accepted. Here are some initial points you should check:

1. Make sure you have enough funds on your bank account or card
2. Make sure that your card is enabled for international and online purchases in USD
3. Contact your bank or card provider and ask if they have stopped the deposit
4. Wait 10 minutes and try once more to make your deposit. Your first attempt might have been stopped due to a communication error
5. Remove your card and re-register it 

We hope that this checklist will be useful for you. If not, please contact Entropia Universe Support for further assistance with your deposit.