Stay permit (humanitarian) can be changed to student visa

Hi guys!

Hope somebody can help me!!

I've been studying in Shanghai so I had resident permit then I had to extend it one month so I went to the Bureau and they gave me a ¨stay permit (humanitarian)¨. Now I went to the school to pay next semester and get new papers for a new visa and they told me that a humanitarian visa cannot be changed to student visa and Im supposed to go back to my country and get the visa there.
Does anyone know something about this?

Thanks a lot!