Unavailable (adjective)

1. Not able to be used, reached, or obtained.
2. Not able to be contacted or communicated with.

Origin:

19th century: from un- "not" + available, on the pattern of words such as unavailable.

Examples:

1. The information you requested is currently unavailable.
2. This product is temporarily unavailable due to stock issues.
3. The witness is unavailable for testimony because they are on vacation.
4. The service is unavailable due to scheduled maintenance.
5. The doctor is unavailable until next week.