If you have SSI, I believe this is just a "check"/you saying (by signing) that you are still doing as you have been doing, that nothing has changed. Everything should continue as it has been, they aren't "deciding" anything if nothing in your situation has changed, just nodding their head "yes" that they should continue sending you a check :-)

Disability Planner: Your Continuing Eligibility for Benefits

I am sorry the woman was so rude to you on the phone and upset you. I wouldn't do anything about her, since you have finished talking to her. I would try to forget her as soon as possible. She may normally be a rude bureaucrat or she may have been having a really bad day and took it out on you, etc. She's the one with the problem, not you.