CSi poor work ethics, negligence and unprofessional

CSi received notice from the tenant that was staying at my apartment they will be moving out on 2018/07/31 and the client served notice well in time as admitted by CSi. However I, as the owner, was told of the tenants intentions to move out on 2018/07/17. CSi did not afford me 30 days notice hence i could not make prior arrangements to serve notice where I stay and move into my apartment as CSi has failed to get a new tenant to move in by 2018/08/01. Now I am faced with a challenge of loosing my deposit because I am not at a possession to pay for two rents. I confronted CSi about this matter that they should take responsibility and bare the rental cost for August as this is their fault and they have refused to take ownership of this matter and now I am left in a predicament because of them. Should CSi informed me that the tenant is moving out on time I would not be in the predicament I find myself in. Should take responsibility and own up to their mistake and bear the consequences of their actions. I have written communication between CSi and myself showing how they are blatantly dissolving themselves of this mess they have created. Now I should run around suffer a loss because CSi's negligence, unprofessional-ism and poor work ethic