To exit S mode in Windows, you typically need to provide an admin username and password. Since you mentioned that there is currently no admin account set up and your IT team is unable to assist you with creating one, you may need to reach out to your IT department for further assistance. They may need to set up a local admin account for you to proceed with switching out of S mode.
If your IT team is unable to help, you might consider reaching out to Microsoft Support for guidance on how to proceed in your specific situation. They can provide you with the necessary steps to either create an admin account or help you exit S mode without one.
Unfortunately, without an admin account, you will not be able to complete the process on your own.