In my experience, old beans will eventually soften. The skins might remain a bit hard (chewy?), but the insides will soften eventually.
What I have found, is not to add salt or acid ( tomatoes, vinegar, etc) until after the beans are tender. I know those items are somewhat controversial as to if they really prevent beans from softening, but in my experience that is the case.
Baking soda does seem to help beans to soften, again, in my experience. I understand it destroys certain vitamins (B?) however.
Try to find the "freshest" dried beans you can. Hispanic markets generally seem to have a high turnover of black, and pinto, beans so they might be a place to go for fresher dried beans.
¿Como como? Como como como.