Why do they insist on treating customers like dirt - I had an issue today that's escalated to the point where I've now cancelled my account - they simply do not care, no broadband for 5 days and they state you got a credit what more do you want? This is why 1000's of people are now moving to BT and Talk Talk
It is unfair to class all the agents in the same basket, Call Centre staff are ones that are continually changed due to many reasons, from personal problems, to medical and obviously to poor performing staff.
That agent you talked to can easily be in the 1 or 2% of the entire staff in that CC itself that are potentially bad or are bad.
If you get an agent who is not forthcoming or shows lack of respect or uninterested, then ask for his/her's Team Manager, if they refuse ask twice more. And then inform them asking 3 times forces that agent to get a Team Manager.
They will usually say "My manager is not available, shall I arrange a call back?".. you will say "no, there has to be a manager always available. I would like to speak to one, or are you refusing me?"
They may give you more rubbish or in some cases put the phone down. If they are still on the phone and refused again. Hit them with this "Then I wish to speak to your CCM or ACCM", if they have been there a while they will know who that is and they will know at this point they f'd up. At this point they have to get that person who is always available (well one of them at least) or else it is guaranteed sacking time.
Requesting the procedure for a full SAR is always a good scare tactic too, but don't use it willy nilly to nice agents. And obviously don't use it if you cannot get something you think you are entitled to when you aren't, because it will backfire on you.