I received a rebate from NexGard in the form of a VISA card. Instructions say to go to MyPrepaidCenter.com to activate. I have put in the required information (card number, expiration date and security code). I keep getting the message "Activation failed, try again". I have no idea why the activation failed. I called the contact number for VISA that was listed on the site but it is an automated voice system that requires the card number and says my number is not active. Any advice on what to do next?