One feature of our new system is that it is first and foremost a Utility billing system, and not designed to handle targeted payoffs such as appliances very well. The payoff order in the system is Gas, then Taxes (if applicable), then Installment Payments, then other Fees.
Customers are welcome to pay more than their bill and carry a credit, but please be aware that on the next billing, the credit will apply first to gas. In order to pay off an appliance, the current contract would need to be voided and recalculated each time.
Our advice: keep that extra money!!