Visa for Germany

I am writing this after having failed repeatedly to contact the German consulate in Karachi in connection with the study visa for my son who has been admitted to Deggendorf Institute of Technology in Germany. With the deadline looming, we are getting rather desperate.
There are currently no appointments available for filing visa application, and all my efforts to get in touch with the consulate through phone, email or website have been in vain. The semester starts in October, and considering that the process of 4-6 weeks of obtaining visa has not started yet, I fear that my son, and a lot of other students, will not be able to get visa in time. This will not only cause great mental stress, but will also result in the loss of precious academic time. The authorities concerned need to look into the matter urgently and help us move the required process at the earliest.
AMMAR HASSAN
KARACHI