Need help to get medicine for an infected cut

Hello,

A month ago I cut my leg on a rusty fence while walking home from work. It was a very small cut, but it got infected so badly that the skin twelve inches away was starting to fall off.
I went to the hospital nearby and they wouldn’t prescribe any medicine at all, even though the infection was very bad and the lymph nodes on my upper thigh were visibly swollen. Instead, they ordered an MRI for some reason and told me to come back next week.
I came back the following week. By then, the infection was much worse and I had to, kind of, hop around. They looked at the MRI and still wouldn’t prescribe any medicine. They said the infection isn’t in my bones so “I should be fine.” They then told me to go to a dermatologist.
I went to a dermatologist, still in a lot of pain, and they also would not prescribe me any medication at all. They took cultures and told me to come back next week. So I did.
When I returned, with bits of skin falling off and spots of blood staining my pant leg from hip to thigh, they told me “Yes. You have an infection. You should go to the hospital.” Again, they refused to prescribe any medication.
Now, the swelling and pain is down, but the infection is continuing to spread. I don’t know what to do.