Credit Cards

Question on credit cards

I have 2 different merchant accounts I use, one for amex and other for visa mastercard and another paypal.

The american express I set up for one merchant as you checkout then select amex for example and continue then you will see a select box for all credit cards again and is this way for all or any you set up new. Hopefully this makes sense again what I want is when you for example select visa upon checkout as you go to next area which is the secure area to enter your credit card info there is a select boz there for all credits cards I want just visa master card or discover in one credit card set up and another credit card set up I just want american express. The reason is when people choose amex and go to next area to enter credit card details there is another select box for visa mastercard discover american express or what ever you choose to appear