Hey sorry for the problem. Yes, we take Visa, but sometimes a red flag gets raised for whatever reason. Fraud protection measures are so tight that sometimes false-positives result, and legitimate transactions won't go through.
Due to privacy concerns, I am not privy to your personal or credit card information. Over time, though, I have compiled some common reasons why transactions sometimes don't go through. Please check UMD's FAQ here to read them. It also gives you information on how to possibly correct the problem by calling them.
Let me know if I can do anything else. And once again, sorry for the inconvenience.