I’m not sure which chat you reached (normally QB does not offer a chat feature), but the Support hours are:

Open Hours: 6am-6pm (PST) Mon.-Fri. 6am-3pm (PST) Sat.

You can get the correct number for your version/question here:

https://community.intuit.com/announcements/1220157

Resolution for 'available supervisors issue: 'I had a terrible interaction with the support chat and would like to complain. They insisted there were no available supervisors, how do I get in touch?' available: Yes.

The available supervisors issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the available supervisors issue yourself by looking for a resolution described in the article. If it is a complex available supervisors issue or you are unable to solve the issue, you may contact us by clicking here or by using other available supervisors support options.

For more information about resolving issues related to available supervisors in Quickbooks/QBO or to get support for the issue 'I had a terrible interaction with the support chat and would like to complain. They insisted there were no available supervisors, how do I get in touch?', click the link below: