My experience with grocery stores and expired produce is the stores are hesitant to give out their expired produce to the average person. The stores want someone that can get the produce on a long term regular basis that is reliable. They generally do not want to throw the produce out but most do because it’s a hassle of dealing with flakey people and that is usually why they say they don't have any to give out.
As others have said visit your local Franz bakery outlet. Ten bucks for a cart of old bread is a smoking deal in my opinion, a cart for me is usually about 40 loaves. I have an old fridge I keep the bread in and its lasts longer that way.