Applying for M Visa

Hello, I am an SA permanent resident with a Ghanaian passport. I was told at the consulate that my inviting company was to provide me a Duly Authorized letter, but the human resources person in China says she has visited a number of agencies and was told this letter is no longer distributed. I went back to the consulate and the gentleman insisted that is not the case. Is there anywhere in particular this document may be processed? The company is based in Beijing, and this is apparently the first time they have had to come up with this letter.