They have a fee for everything, and I mean every little thing. Want to hand in your notice? We need a fee "to process your notice". Want a reference for your new place? We need a fee. Want to end your tenancy? Guess what? We need a fee.
Maintenance never actually gets done when requested. Also our flat didn't even have a gas safety certificate for 6 months - I kept calling them to tell them to get one and they had the cheek to tell me that it was my job - I'm the tenant!!