There’s no match for that Service Tag or Express Service code

Hi

I recently purchased a Dell Inspron 7559 laptop. It arrived on the 31st August. The issue I have is that the service tag is not recognised on the Dell site. I get the following message when I enter the service tag: -

There’s no match for that Service Tag or Express Service code. Retype the code or select your product below. Allow 48 hours for new devices to register on our site.

It's been well over 48 hours since the machine was registered.

Please help.

Many thanks.