Agent wants me to pay a hourly rate??Can he do this??

Quick history I am the landlord property fully managed by a letting agent. Tenants bought in pets without permission they stayed 6 month then left
owing rent and kitten damage to my carpets.
The tenants are refusing to pay the damage out of their deposit so I have
asked the agent to do a dispute.
I had a letter back from the agent today asking me for £25 per hour in
charges to take this on and to open a account with
depositprotection.com to get a landlord ID so they can deal with it for me.

I have now moved back into my flat and will not be renting it again so I really do not understand why I need a account with depositprotection.

Can someone tell me if this is for real or is the agent dodgy??

Thanks so much for your help
Lori