Shopping in China

i want to buy things from china. i have passport, character certificate, Bank statement and i can also give you guarantee from any other Pakistani citizen. i just want to buy some things and sell it in any market in Pakistan. Moreover i dont have any company here in pak and any business partner in china so i cant get an invitation letter. i want to apply for visa but agents are refusing ......what should i do? Do i have to visit embassy? If so then whom should i meet in the embassy ?