def customer_item_quantity_overage_cost(item_code = nil, code = nil)
      item = customer_item(item_code, code)
      return 0 unless item
      overage = customer_item_quantity_overage(item_code, code)
      item[:overageAmount] * overage
    end
def customer_item_quantity_overage_cost(item_code = nil, code = nil)
      item = customer_item(item_code, code)
      return 0 unless item
      overage = customer_item_quantity_overage(item_code, code)
      item[:overageAmount] * overage
    end
The current overage cost for the given item for the given customer.

item_code must be provided if the customer is on a plan with more than one item.

code must be provided if this response contains more than one customer.