They are doing you a favor. I bought my kid a Dell laptop (xps13) for college and 6 months later the battery life dropped from 12 hours to 2 and Dell support said it was normal and refused to do anything about it. That was after the original order which was supposed to take 6 weeks for delivery (bad enough) actually took 14 weeks. It arrived two days before they left for school. Worst experience ever.
The replacement MacBook Air was delivered to their dorm the next day and has been flawless since (over a year now). It actually cost less too.