Are you a Chinese who can't speak Chinese? If so, there are a lot of reasons for learning our mother tongue. Although English has became the language of business, culture makes us wealthier and more tolerant. If you can weather this, you'll have potential to work in any big firm.

Sorry I thought you were a Chinese. That really turn the table on them. They probably never been in racially-diverse workforce and your place has been a Chinese-dominant environment, which makes you "hard to be noticed". I am sure they feel guilty having you left out sometimes. Take some time to adapt. You have nothing to do with it man, you have done your part trying to mix in, but never do something which never meant for you (e.g., take Mandarin class) to ingratiate people.