tricked by agency (urgent!!!!!)

[wertyub]

We have signed today a contract with estate agency to rent a flat.we signed all documents and after that we received keys.when we asked if they come to check the flat ,they said it was allready checked.(looked strange to us),so we went to flat and find a bathroom with a wallpaper falling from top,and bathroom in bad condition(we were not able to see it before because the agent who was showing the flat said,HE CANT SHOW THE BATHROOM, because somebody was inside).We were disgusted so we called back to agency to tell them we would like to cancel the contract and have our money back.They said NO and told us that they told lanlord to fix it.When we said we feel betrayed and tricked by them and thats the reason why we want our money back,not just because of the bathroom,they said THEY WONT GIVE US OUR MONEY BACK,unless lanlord says it is reasonable.
I DONT KNOW WHAT TO DO.WE PAID RENT FOR 6 MONTHS (�4800) AND NOW THEY SAY IF WE TAKE THEM TO COURT WE LOOSE.
CAN ANYBODY HELP PLEASE ???