What should I do in the face of harassing phone calls and text messages! ! !

The naive girl turned to everyone for help. I work in the business hall of Hunan Mobile Company, and the front desk handles all kinds of business for customers. I often meet all kinds of people. I will encounter all kinds of troubles. These are small problems, but when I met such a person, my life changed completely. . . Because after the sales staff at our front desk handles the business for the customer, the customer's mobile phone will receive a short message about whether he is satisfied with our service. If the customer's reply is not satisfactory, we will pay a return visit to the dissatisfied customer and ask him what makes him dissatisfied with my service. A few months ago, I met such a customer who came to me, paid the phone bill and left. But it didn't take long for the manager to tell me that a customer complained about me, so I called him after work and asked him what was wrong with my service. As a result, his answer made me laugh and cry. He said, "You have no problem, but I don't want to satisfy you." I said nothing, and then I apologized to him. I said I would be more careful in my future service. I was deducted for this complaint. I thought it was over. As a result, since I called him last time, he knew my phone number, so he started calling me when he was free. At first, he just looked for my phone number. I put up with it, but he didn't stop there. No matter I go to work at noon, I sleep and I rest, he will call, and he hangs up when I answer his phone. So I texted him and asked him why he kept harassing me. He replied, "I just want to harass you until you change your mobile phone number." Last time a woman in your company was harassed by me to change her number, and you are no exception! " . I am really helpless and speechless. . . However, he pushed his luck and sent me obscene text messages every day. He knew my name and added it to the message. The contents of those messages are really unsightly and filthy. . . Until now, he still harassed me like this. He was still calling me when I posted, sending that kind of message. . . My tears came out again. Call 1 10 if you want to call the police. But does that really work? 1 10 is an education at best, and then the man will send text messages and call me to harass me. I want to change the number, but this number is the employee number of the mobile company, which is really troublesome to change. . I really don't know when it will end. I have a classmate who is a law researcher. He said he could sue him. Well, that's also very troublesome. . . What should I do?