Revise the following paragraph so that it includes a vertical list using any method you prefer.

The Customers First work group studied the high number of customer complaints about our Service Center and categorized the causes into four major groups. The first group is the employees who have slow response times both to phone calls from customers and to in-person visits to the Service Center. The second group relates to employees who can't assist customers because the employees lack information or knowledge of the company or its products. The third category is emploee manners; customers complain that employees respond rudely to customer questions and concerns. The final category is employee failure to resolve the customer's concerns. Because we can't except to fix every problem, we can expect to provide polite, prompt, knowledgeable service to our customers.