I work in property management and would not even consider entering a tenants apartment without the correct 24 - 48 hour notification and consent - you also have the right to refuse access unless in emergencies or works being required to the property and even then they still have to request reasonable notice, but you can insist that anyone entering your property does so accompanied or in your presence.  The owner does not have the right to enter.

Photograph the damage immediately, make a statement listing the damage caused and the theft, assuming your new table has been damaged if the wall has been? (you would have thought the owner must have been aware of what furniture is his)?  Send a copy by recorded post to the manager and managing director of Foxtons head office and put a claim in for the full cost of the table and chairs and compensation for tresspass, also demand that they send someone out to repair the damage. If you do not get a satisfactory reply keep ringing head office or go in person - be demanding and keep on at them.

 It is outrageous, it is unprofessional and is also theft so also go to the police.

 Estate Agents have a bad name but Foxtons seems to be top of the list.