I have recently moved out of a property which was managed by Cottons and I am so glad that I have left them. They treat their tenants with thinly veiled contempt and any attempt to get information, repairs or refunds from them is like getting blood from a stone.
I have given them two stars instead of one because of one very pleasant staff member who surprised me greatly, and in my opinion is a diamond in the rough.
Otherwise, avoid this lettings agency if at all possible.
What agent could do to change your mind?
They could have been generally more pleasant, helpful, had better manners (like not putting the phone down on tenants) and known how to run a lettings agency.