If I could get another 6-month extension, this should have been for sure, my manager and teamleader told me about this. Acutually, they did submit a report to the high level management for my case, but got rejected, the reason is "No exception". Perhaps some other managers were more capable to handle this kind of situation and could keep their guy(very very few, as far as I know), but my manager himself just got promoted for 8 months, I think he had done his best for me.
Another point is, I don't have to prove my skill to you or anybody else, I got hired within one month, this is the answer.