Suspicious share trading

Does anyone have any experience dealing with International Trading based in Hong Kong? I signed up with them to do share trading on the NASDAQ stock Exchange. In November they bought 1470 DCIX shares on my behalf. However now when I have asked them to sell the shares, they claim that there is a new ruling in place for DCIX shares, in that shares must be sold in blocks of 2000. So they want me to buy another 530 shares and then the will sell the 2000 and refund me my money. It sounds very suspicious.