Your tickets are closing because your account is still compromised.

https://steamhost.cn/help_steampowered_com/en/faqs/view/70D8-0BCC-C47E-F498
Closed by a Malicious Individual
''A ticket can be considered to have been maliciously closed when someone other than the person submitting the ticket closes it.

If your support tickets are being closed without response from the Steam Support team, and you're not closing them yourself, it's likely that someone else is closing them - perhaps maliciously. In the very rare cases where this happens, it can usually be attributed to an account hijacker that is trying to make recovery difficult for the account owner. While this is a serious situation when it comes up, it's also usually a simple matter of securing your computer and email account before getting back in touch with Steam Support to recover your Steam account''

Secure your account with the following steps:-

1. Scan for malware
2. Check that the email and phone number on the Steam account are still yours.
3. Deauthorize all other devices https://steamhost.cn/twofactor/manage
4. Change passwords from a trusted/clean device.
5. Generate new backup codes for your Mobile App https://steamhost.cn/twofactor/manage
6. Revoke the API key https://steamhost.cn/steamcommunity_com/dev/apikey (the domain field should be blank)

You signed into a shady site and granted a malicious actor access to limited functions of your steam account. Follow the steps J4MESOX4D provided and you will be good again. Steam support pretty much always replies so it's probably someone wanting to maintain access.

Accounts are phished not hacked.

You gave away all your account details.

The account name, the password and the KEY to the door, the Steam Guard Mobile code giving them access to the account.

How? by either logging into a known scam site or sites, tailored malware on your PC, the vote for my team scam, you have a pending ban scam on Discord, free knife click the link etc.

How does Steam (a program) know it is not you when all the account details are correct? It doesn't, therefore any action taken on your account is seen as you doing said actions.

The alternative is not plausible:

1) Someone would have to "GUESS" your account name from "millions of possible combinations".

2) Next they would have to "GUESS" your password from "millions of possible combinations" and then match it to your account name with "millions of possible combinations".

3) And finally they would have to "GUESS" the Steam Guard Mobile code "which changes every 30 seconds" to match both your account name and password to then have access your account.