To remove previous credit card information that maybe left over from the previous gateway after switching, you will go to
  1. onMessage 
  2. Settings 
  3. Store 
  4. Shopping Cart 
  5. Uncheck Credit Card 
  6. Click Save & Exit 
  7. Recheck Credit Card 
  8. Click Save & Exit 
Once you do this your form Store should display with the correct Credit Card Payment options and you will be able to access the Secure Payment Page