What is meant here is the account balance would magically change back to what it would have been if no deduction has been made. Since you have no record of your account balance you don't have a means to prove it one way or the other. Yes, it's frustrating when they don't follow GAAP rules regarding account activity, they are IT people not accountants, but it is what it is. Seeing that years ago, I started maintaining my own account spreadsheet and make sure all expected activity happens and can point back to specific transactions. Many people blindly expect the Marriott records to be 100% transparent, they aren't. If you value your status/points, then take action to monitor/track your activity.