I have a crack on my apple Magic trackPad. Is there a service to have it repaired or will I have to purchase a new one?

this is a fault of the design. I have had three replaced in our business one the same day it was opened, there was a small blemish on one side of the surface and within ours of using it a crack appeared and travelled across the trackpad. I have seen it also happen in an apple store a person was using the trackpad and a crack appeared all they did was press to click as you should be able to and a crack appeared.. The apple staff member quickly grabbed the track pad and swapped it.

If you turn the trackpad around 90deg and watch from the side as you press the trackpad itself aluminum flexes! it is very clear when you press down especially if you press towards the top most raised part of the trackpad. This is why we make sure all of ours are touch to click not press to click in settings..

Apple will not repair it, if it is under warranty then take it into your local Apple Store and ask to have it replaced however with cracks it is difficult to prove it was a manufacturing issue and not owner abuse.

Good luck.