American Express's merchant pricing is determined by the business' type and is completely independent of the merchant's choice of processing company....
Some card issuers have been hit very hard by the debit interchange limit, losing hundreds of millions of dollars, while very few have been unaffected....
Global Payments' data breach should prompt you to act and protect yourself against potential fraud, but not to overreact and create unrelated issues....
The Global Payments hackers may not have been able to gain access to all of the data they needed, but the clean-up process will be hugely expensive....