Inept Billing Software at Sprint

Chris writes: "I am a Sprint customer signed up for automatic payments, and over the past week I've found that Sprint has a computer system that does three ridiculously inept things from a programmers standpoint. First, they send a "Do not send payment...this amount will be charged" bill and a "Disconnection Imminent" notice for the same amount within a week of each other. Then when customer service is called, everything appears fine to customer service and they assure the client that everything is fine. Finally, the computer system shuts down a customers cell phone for lack of payment, even if the customer has a credit card on file and has given Sprint authorization to use it.

What's the worst experience Slashdot users have found with billing systems that don't make any sense?"