I have the same problem. I want to change my number, but there is no easy way to do it. Why do you need to contact me for updating my own contact details? I don't get the logic for that. Do you mind explaining please?
Are you a landlord or owner of an apartment or an agent? Have you listed any property on CommonFloor or currently using any CommonFloor services? If yes, then you can give your contact details and the concerned person will contact you.