Wait online! Steam account was stolen, I want to complain. What does this mean? How to solve it?

In customer service, if you forget to change your password, you will send a verification code to your mailbox. If you choose one below and don't use this mailbox, you will enter a complaint. You need the original fuel tank and the mailbox you are using now. Finally, you have to declare that this is your own account. When I appealed, I provided the email I received after buying the game ("Thank you for buying on Steam!") That) and the corresponding Alipay bill, as well as the email of abnormal login and the email screenshot of modifying the mobile phone number. By the way, it's best to make a presentation online in English (I wrote it in both Chinese and English translated by Baidu). After submission, I waited for about 3 days to receive the customer service email.