Money Deductions

In 2010 I left Kimberley and gave my house to Just Letting to rent out and manage. The got me a first tenant which moved in May 2010 and moved out in April 2015. In the 5 years she has paying late all the time and Just Letting didn't border to let me know when she had made a request to pay late. I had to call all the time to find out. In May 2015 another tenant moved in. He always paid late and sometimes pay in half's. In October 2015 Just Letting issued him with an eviction order and he was supposed to move out end of November 2015. In his last month he didn't pay rent at all and the agent told me ill take the deposit after moving out. He moved out but left the house with many defects and had to repair. The deposit paid for the repairs as per contract but Just Letting paid themselves cancellation fees from the deposit. The Deposit Payment clause in the contract does not says that they must just pay themselves while I am still owed money. I approved the payment of the repairs and cleaning services, as a Landlord, but I did not approve payment of cancellation fees. They must get that from the tenant not from the money due to me.