Eastern Seed & Vet Ltd - Chipata, Zambia

We have a chicken that has been sick for more than a week now. It could not move, it'neck got into a weird position and it's eyes could not function anymore. We tried getting it some meds, anti biotic inclusive, but we only got it to have it's eyes work again and it's neck got better but not as a normal chicken. Now it's eyes are going bad again, it still won't move and we seem to have tried any possible solutions. How can you help with this situation?