"Case under ownership" - how long to wait for response?

Hi,

Does anyone know what the current response time should be if I have a "case under ownership"? I called Saturday evening about my computer, which still has over a year of premium support left." The representative was unable to resolve the specific issue (the computer battery drains about 13%/hour while in standby mode) and said she'd escalate the matter. I received an email stating the case was "under ownership" Saturday evening, and I haven't heard anything back. On Tuesday, I sent an email asking for an update or when I should expect to receive directions/contact, but have not received a response.

Thanks!