There are a few reasons why your call might not go through to a certain number. One possibility is that the recipient has blocked your number, which means that you cannot reach them over traditional voice calls. Another possibility is that the number has been disconnected or taken out of service, which also prevents your calls from connecting. In either case, the best thing to do is to try reaching out to them through other methods of communication (such as text or messaging apps) until you can get in touch with them via phone.
Verify that the number is correct. You can do this by contacting the person or organization to verify that the number you have is correct. It is possible that they may have recently changed the number or that you accidentally misdialed it.
Check the device and network coverage. You can do this by attempting to call the person from another phone or using a different network, and seeing whether your call connects. It is also a good idea to contact your service provider if the problem persists, as they can investigate any potential network-related issues or account restrictions that might be preventing you from calling the particular number in question.
The above tips should help you troubleshoot the issue if your calls are not going through to a certain number. If the issue persists, it's a good idea to contact your service provider's customer support team, as they can provide additional troubleshooting steps and escalate the matter if needed.