6-months internship has nothing to do with what was promised
There are two people who can help you


Your immediate manager
Your advisor (or tutor if you don't have one)


Talk to your manager first about the requirements stated by your university, and how to translate your work into a working paper or report worthy of submission in an academic institute. I am sure he will be of help.

Then try talking to your advisor/tutor on whatever was discussed with your manager. He/She can advise you on planning your report.

I had been into such a situation, and my advisor suggested a way to tweak my working to do some additional tests/work. That extra work made my work eligible for an academic report.