When you access an open Steam Support ticket, you have the option to mark it as solved by closing it. It's suggested that you do not close a ticket yourself unless you're sure that the related problem is solved.
Support tickets will close automatically if they have been waiting for a user's input for 14 days. Tickets will not automatically close if they're waiting to be addressed by a Steam Support agent.
After addressing the problems that Steam Support can help you out with, an agent may close a ticket. This will typically only be done when the problems that are being presented are outside of Steam Support's scope. Unless your support ticket includes abusive content such as harassment, spam, extreme vulgarity, or threats, a Steam Support agent that will be closing a ticket will state so explicitly.
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.
Closed tickets can't be reopened - if you closed your ticket mistakenly, please create a new ticket and include your closed ticket's Ticket Number (HT-####-####-####) in your message.
The only way to close a ticket that was submitted from a Steam account is with access to that same Steam account. This may be someone else who has you login credentials, or it could be through remote or physical access to a computer that you've saved your login credentials with.
Using Steam's Account Security Recommendations as a guide, secure your computer by scanning it for malware. Once you're sure that your computer is not infected with malware, secure your Steam account by updating its password to one that you haven't used previously and don't use with any other accounts. Updating your password will also force anyone who is logged in on a different computer to log in again, effectively removing any hijacker's access to the account.
Resubmit your Steam Support ticket once your computer and accounts are secure.
To close a ticket submitted via email, the person closing the ticket needs access to it via the unique ticket access link that's sent to your email address when creating the ticket or whenever it is updated with a response from Steam Support.
First, it's important that you consider a ticket whose access link may have been viewed by a hijacker as insecure. If you think that a hijacker has been viewing your emails, you should close any tickets that you submitted prior to securing your computer and email account.
In addition to our normal Account Security Recommendations, make sure that the hijacker did not set up any forwarding rules to automatically forward all support related emails to an email address of their own.
While it's probably not a good idea to abandon one of your email accounts to a hijacker, you may choose to create a new email account or use an alternate account to contact Steam Support while you take measures to secure your original account.
Once you're sure that your computer and email account are secure, submit a new ticket to the Steam Support team.