If you want to fix the wireless customer not available issue then below are some solutions through which you can do it very easily:-
1. The first thing that you can do is to check the number that you have dialed and make sure that there is no mistake in the dialed number.
2. Then check is the person you are calling is busy or not. If you receive the message “the number you have dialed is currently busy” then the person is talking to someone else.