how to fix headset sign nokia 6230?

my nokia 6230 has just been on headset for a couple of days now, cant hear a ringing on earpiece only on loudspeaker. there is a headset symbol in the middle of screen, and when on loudspeaker, a headset word on right button when talking. rang nokia they said could be hardware or software problem, i have put a headset on the phone but still cant hear. phone is 4 years old now, still a very good phone, please help