Bought and paid for an item from jessmotor.com in china 16/11/13 and I have not received

Hi,they said they send it ,and it got lost in customs in the uk,said they would send me another,five weeks ago and send me tracking number (rc149790688cn) which do not work hear.they email me three weeks ago,and said the number is working in china,and that my item had cleared customs.the number still not working hear,and the item should off been hear two weeks ago,and they will not answer me by phone nor email.i do not think they send it at all.does anyone know this seller,(jiangsu sunshine motors .co.,ldt or tel 008651088726500) or can anyone in china try the ems tracking number and see if it does work there.or can anyone advise me what I can do,or can anyone do anything for me.i paid $830 by bank transfer to this seller and I do not want to let them off with scamming me.if anyone can help please email me.thanks