Cover beans in twice their volume of water and soak overnight. Drain and rinse. Add beans to a large pot and cover completely with water. Add vinegar. Bring to a boil and cook until soft, about 3 1/2 to 4 hours, adding water as necessary. Reserve 1 cup of the liquid. Drain the beans. Heat olive oil in a large pot over medium-high heat. Saute the garlic, onion, tomatoes and peppers until softened, about 6 to 8 minutes. Add reserved liquid and the beans and simmer until the tomatoes are completely broken down, or about 20 minutes. Take 2 cups of the beans and mash them using a potato masher or a fork. Stir them back into pot. Add oregano, black pepper, and salt until thickened, about 5 minutes more. Stir in the cilantro just before serving.