Don't be sorry....BUY me something.
For non-fatal things like hair appointments (or basically almost anything), making the situation awkward is not going to do you any favours. Acknowledging the inconvenience while putting the person at ease is more likely going to persuade the person to make up for it. And we are generally more impressed by how well someone "fixes" a mistake, than if there had never been one in the first place (which is impossible, as we all make mistakes).