I'm so sorry to hear that you are being called a demon for hearing voices. I want to tell you that it is not true at all, you are not a demon.
As a mental health professional with strong religious belief (Christian), I must sadly admit that sometimes some people within the religious community are misinformed or have misunderstood about mental health issues, and that makes them giving hurtful or even harmful suggestions to the person facing such mental health issues. It is important for us to recognise and learn about what mental issues are, and how we can help.
Speaking of which, I want to say I'm happy to hear that you recognise you are facing this issue of hearing voices. Recognising and admitting our issues or problems doesn't make us weak or bad, instead it takes a strong person to realise and recognise that we face problem, and we need help. I hope you can seek for professional help for you to deal with this issue. Finally, I want to affirm you that God loves you and He cares for you. Perhaps at this moment you may not be feeling like this is true, that He loves you, especially when you are still struggling with your issues, but I know that it is His plan that you can receive and accept this love, and He will make His love known to you. Do not stop getting help for the issues you are facing, and do believe that God loves you!