You can refuse a booking request by clicking "Reject request" in the "My messages" section of the corresponding booking request. You must specify a reason (it will not be published or displayed to the guest). The Workspace2go team will then look for alternatives for the guest.
If you have an equivalent alternative space in the same building, you can send it to the guest via "My messages". It is best to send a request for the correct space again so that all data are correct.