need advice on my neighbour’s dog

My neighbour has a female boxer. They bought it and breed her when she was just under a year old now, took away the puppies and left her under the sun, under the rain with a metal chain tightly around her neck. She is never let out, never walked, never loved. My family have voiced out and we also offered to walk the dog. I work from home so I observed them a lot and I am free most evenings and I am more than happy to do that. Her nails are long and grown. She's getting skinnier day by day and leash probably 1.5m. My heart breaks and what should I do? Should I call someone on this matter or should I just let it be because it breaks my heart every single day to see her like this. Just imagining being tight outside the house under the rain and sun or fogging and never been walked. What should I do?