Maximum number of tourist visas

Hi, I am wondering if there is a maximum number or a limited number of tourist L types that one can get for China? I was in PRC on two occasions with 3-months' tourist L types and when I went to HK to reapply for another tourist L type they didn't give me any. Apparently I had stayed in PRC for too long as a tourist. I never knew that there was a limited number of tourist L types one can get. Is this really true or did I just happen to have a very crumpy official when applying for my L type?