1. Have you tried calling up the HR department in Deloitte to enquire, or did you just stop at the website? Have you sent in your CV? If i'm not mistaken, a CGPA of 3.75 is pretty good and it would be quite bad if they did not at least invite you for a first round.

2. Being able to read/write/speak Mandarin is a huge advantage in any industry now. But that doesn't mean you cannot be proficient in English as well.

3. As Garfie mentioned, you've only yourself to blame for missing out on the 2 employent opportunities with PwC and KPMG. Any interviews, face to face, over the phone or otherwise, should be taken seriously as it gives the interviewer a glimpse of your character.