Are you at RAL? If so, there is a system for tagging bikes and removing them if no-one has used them and shown that they have by removing the tag after a period of some weeks. It was used to some effect last summer, but may not happen again without a request being made to suggest that it’s needed. It is either Estates or Security who initiate it.
In any case, to contact Harwell Campus Management (landlord) you need Dawn Crawford: 01235 250170 or dawn.crawford@harwellcampus.com (email is usually better).