Career Advice Career Doctor

Mature student being back to work after 47


I'm a 47 mature student, just finished my 4 year-study in a master of business, and getting back to work - retailing (my most experience field).

But over 8 months job hunting, I have sent out almost 1000 application letters and emails to all listed retail companies in HK, but only gained a few interviewing chances. Too often,  these interviewers just took 5 minutes then jumped to the final question and said "go home" waiting their calls. 

Conversely, some took almost 1.5 hours for writing their assigned business proposal tests and spend 1.5 hours oral tests, which seems checking any uncovered things from my CV line by line. Totally exhausted and stunned for these prolonged interviewing and job hunting, so painfully,  I haven't get any feedback so far. I understand to wish for change will change nothing, to make the decision to take action right now will change everything! But what actions that I can go and what kind of job that should be more suitable for a mature returned worker - like me! Thanks in advance for your reply.