X2 visa to go to China from Japan

I arrived in China with a tourist L for 90days. I wanted to extend my stay as I wanted to enrol at a local learning centre to learn Mandarin. I was advised to travel to Japan to renew my visa and apply for a X2 from the CVASC in Tokyo.
I took all my documents with me passport, proof of enrolment at the learning centre along with all the relevant photocopies. I submitted my application.
I have received a reply from the Chinese Embassy stating that I have to stay in Japan for a minimum of 1-3 months before they can look at my application. I find this very very strange. Does anyone have any advice on what I can do?