Master Card Debit Gift Card not working

[Gum Ass]

I tried to put my Master Card Debit Gift Card (which I have already activated using the website www.prepaidgiftbalance.com) into Steam recently, and I got the following message:



Your purchase has not been completed. Your credit card information has been declined by your credit card company.

Note that in some cases, your credit card company may put a 'hold' on funds in your account, but you will not be charged. After correcting any errors in the information displayed below, please try your purchase again.



Help?

[76561198218426745]

The address you entered onto the card must match the address you enter onto Steam exactly; your name, address, and phone number must be identical. In addition, make sure you are entering the CVV2 correctly.