Whom they have injured they also hate.

People often end up hating the person they wronged. The mechanism is simple enough: your continued existence is a reminder of something they would rather not have done, and it is easier to decide you deserved it than to sit with having done it. That is why an apology rarely comes from the person who owes it, and why the coldness increases over time.

If someone has turned against you for no reason you can find, consider that the reason may be something they did. You are unlikely to get an apology. Knowing the shape of it can at least stop you searching for a fault of your own.