Sometimes you do get an occasional response from the department saying that they're going to exceed the time limit. I know that an article came out recently saying that they weren't doing that. They started doing that. They've now stopped doing that again.
I often follow up with them via email, because I know that attempting to resolve the problem is a prerequisite of going to the Information Commissioner or Privacy Commissioner. However, complaining to the Information Commissioner and the Privacy Commissioner is not an exception to getting the information. It is part of the process. You will not get your information unless you make a complaint.