In the case you're speaking of, where there are large sums of money, we operate a system called the “large value transfer system”, which is available to our membership. They make that service available to consumers and businesses, and in many cases it's taken up by businesses. What it assures is same-day, real-time funds, and it cannot be revoked.
For example, if you were closing a house deal and you needed to ensure that the vendor received those funds today, you could go in and do a wire payment to ensure that it is made. So there are some options available.