My home insurance policy renewal listed the various payment options. Each of them included a $5 service charge per payment. However, when I received the premium due notice (bill), another $5 was added to the amount of the payment.
The balance statement which came with the bill listed the amount of the previous payment applied toward the policy premium, minus the amount of the service charge. The customer does not receive an itemized listing of actual payments and charges which makes it difficult to notice that one is paying double service charges.
Hard copy evidence of the "mistake" is in my possession, naturally.