Converting L type to X2 type

Hi!

I was told by a Chinese language school that I can convert an L type to an X2 type in Beijing with their help, and they advised me to do so in order to study at their school. I am still unsure about this, as I did not get any confirmation at the Chinese consulate in Iran whether this is the case or not. I only need this visa for the summer before going to uni.

The school is Beijing Global Village School, which is pretty decent (been there before), but I have never had to go through visa stuff with them.

Could anyone confirm whether it is still possible to convert L to X2? And does that apply to all nationalities?

Thank you so much!