Diamond Trading in Chinese – Beginners

I can choose 3 pieces from the list you gave me.
我同事去了你们香港的办公室取货,但是发现不是100%肉眼干净的。
My colleague went to your Hong Kong office to collect the goods, but found out that the goods weren't 100% eye clean.
我同事去取货了,但我定的货一共五个,怎么只到了三个?
My colleague went to pick up the goods. I've ordered 5 pieces. Why are there only 3?
我不会还你的价,但是你必须确保星期三之前我能拿到货。
I won't try to take down the price, but you have to prommise me that I can get the goods before Wednesday.
我往你们公司的账号转了2万美金,但发现转多了,多余的美金,可以给我现金么?
I've wired 20,000 USD to your bank account, but found out that I've transferred too much. Can you give me back the excess amount in cash?