Visa dilemma

Hey! I'm a Pakistani citizen and I wanted to apply for a visit L to attend my friend's wedding last summer. The Chinese embassy said that I need a permission letter from their Chinese Foreign Affairs office in order to apply for an L. But the office told me they can't give it to me because personal invites are not allowed? If I want to come to China I must join a tourist group, or come on a business M or as a student. This is so ridiculous! Can't I come alone on an invite by my friend??
Regards,
Anum.