Why it takes so long to check my Evidence , Its Been 2 months!!!!

Hello, I hope that you could help me, I have nowhere else to go.

It all started 3 months ago, when I first applied for student finance, I did everything on time, just to be sure I'm on track.
On 10.05 student finance asked for evidence, that I gladly posted with next day delivery. I knew that it can take some time for them to check it, but i did not expect for them to send it to another department and make my application even longer that it is, it has been months of waiting for something to happen. I have been calling them every week and every week it's the same story, that I will receive update next week, but nothing happens.
I'm starting to worry about this situation, that I'm not going to get student loan on time.
Has anyone been in this situation or knows what I should do?

Many thanks in advance.