1 There are fee services (A) - Where is the customer service or maintenance of the goods sold, and charge retention money to the customer, is for such.
2 Contract Services (B) - Where is the customer service or maintenance of the company to sell merchandise, in accordance with the contract with the client company entered into the book, and charge a fee to customers in this category.
3 free service (C) - Where is the customer service or maintenance of the goods sold in the free warranty period, free charge to the customer, in this category.
