Tracking number RC141840152CN

Hi I seem to have the same problem as everybody else,but i have been waiting since the first week of January for my package to come? The seller keeps giving me different tracking numbers when i ask him where is my item? First it was RA777487640CN,then it was RC060007831CN which showed it had been delivered to the Uk 2 weeks ago to someone in Sheffield?,and i live in London,and the 3rd one is RC141840152CN,which shows me the same information as the first tracking number did,and has the status Null Can.All the seller can say is be patient,but it doesn't take nearly 2 months to deliver an item from China, as i have ordered so many times before and had it within 2 weeks.So if anyone could shed some light on this for me it would be great.Thanks