Inspiron 5406 2-in-1, Service Tag not recognized?

I purchased the above referenced computer from Dell.com and the service tag and express numbers are not recognized when I have talked to Dell Customer Care or Technical Support. The last call I had last week the Dell person mentioned that this needed to be fixed by the Dell Tag Team but they could not contact them at the time.  My question how can I get this issue fix for a new computer that I just purchased from Dell.com? I have made several call to Dell as well as online chats with no success.