I am SO sorry to hear this. I work in another Uni and if I was you I should get onto your Student Union and create merry F.... E mail your VC.
Can you get a friendly tutor to email the Uni staff and point this out and question the whole reliability of the Security in place. Competence, fit for purpose etc. There will of course be 'disclaimers' everywhere but, as a previous post points out, if this was harassment of a student and the CCTV was off or not available then there would be hell to pay....
It won't bring your bike back but it might just make them sit up and take notice... Good luck and again I feel for you.. Graham