Milk always goes bad a few days before expiration

It's very frustrating. It's just my boyfriend and I, but we buy a gallon since a half gallon isn't enough. We keep the fridge cold enough and I'm starting to think it's just the brand(we only have 2 grocery stores). They do sell Borden milk, but even that goes bad a few days early and that's a name brand. Maybe it's how the store stores it before stocking, idk. I live in a small town and the nearest walmart is like 45 minutes away. I'm not about to waste gas when I can get everything I need here. We always end up dumping almost a quarter of milk down the drain because it went bad early. I hate wasting anything and it pains me to do so, but neither of us are gonna drink spoiled milk. No point to this post really, I'm just frustrated