Could you explain in more detail the status of the phone.
Is it connected to the WLAN, does it get a IP, could you ping it.
In the controller report, GUI > Reports > Clients > all Clients.... could you see the phone, could you post a screenshot if that is the case.
Are you able to connect with another device i.e. laptop to the SSID.
What are the radio settings, 2.4/5GHz, channel,....