I am unable to connect my payment gateway to my bank

I am using Bank of America. Bank of American only uses First Data to process online credit card payments. First Data only uses "Global Gateway" as a payment gateway system. Your "Membership" plugin only works with "Authorize.net, Free Subscriptions, PayPal Payments & 2Checkout" as gateways. How can I get Global Gateway added to this list of gateway options or properly configure the plugin to accept that gateway without spending an additional thousands of dollars to have you folks customize it?