Why does the US not help Africa?

A man from South Africa came in to our room in Skypeland to claim that the US does not ever assist Africa; it only promises money but never delivers. He claimed that the US had promised 50 million dollars to Africa but had only given one million dollars. I asked where this was, and he had no information. I looked at the official statistics, and the US government budget for aid for sub-Saharan Africa alone is 5.1 billion dollars:
http://www.usaid.gov/locations/sub-saharan_africa/
There are billions more being poured in there from American foundations such as the Gates Foundation, of course. This also does not include US indirect aid through the UN, the World Bank and the IMF. This does not include American contributions to NGOs like the Red Cross. And it does not include all the other African countries, like the African country of Egypt is the 2nd largest recipient of US aid, getting over 3 billion dollars a year, which is not included in this total.

When I asked him more, he switched to Sudan and wondered why the US was not doing anything in Sudan. When it was pointed out that the US is trying to correct the situation in Sudan (for example, putting pressure on offenders: http://news.bbc.co.uk/1/hi/world/africa/4952522.stm), he switched to complaining about New Orleans.

When I pointed out that New Orleans was not part of Africa, he said he could complain about whatever he wanted. When I tried to explain, he cut me off repeatedly. I could not discuss it since the room was repeatedly attacked by a hacker from India who just recited a memorized anti-American patter over and over in a monotone voice without breathing. Every time he came in the room to do this, I just turned off my sound so I would not have to listen. I think this South African was trying to play the "racism" card against the US by bringing up New Orleans. Somehow, someone from South Africa does not have a lot of authority to lecture the US about racism, frankly.

I did manage to ask the man from South Africa why rich South Africa did not help their poor African neighbors. Of course, he had no answer to that.