I just bought a new bicycle. While I was fiddling with things (removing tags, mounting a light, etc.) I noticed that the boot on the rear brake cable was loose. When trying to reseat it, I found that one of the strands of the brake cable was broken, and poking through the boot. Furthermore, the cable is un-twisted just before the bolt that clamps it to the right side of the brake. These seem like very bad things to me which I should immediately get fixed (and complain about). Am I correct? Is the bike unsafe to ride?