Rates as low as 1.67%. No Statement Fee! Simple Application! 24/7 Support! Same Day Approvals! Merchant accounts and credit card processing at Diamondcard International. We are providers of merchant accounts, credit card and debit card based payment processing services for U.S. based businesses. Our objective is to offer merchants a level of professionalism and service no other payment processor can equal. We offer the most competitive rates in the industry.