Thanks andrewlutonuk,
Its' nice to know that we were right. I have also received a reply from TomTom Customer Services which I have copied below.
"Apologies for the delay in response; I can confirm that I have received your case back from our Second line technical team.
Unfortunately I am not able to offer you an immediate resolution for the issue with the fuel price service.
I am afraid that you are correct; and the errors occurring are a problem with the fuel price downloads on our server.
The Second line technical team have logged your case and the issue is currently under investigation
Many apologies for the continued inconveniences; I will keep your case in my inbox so that I can update you on the situation as soon as we have some more information.
Apologies again for the inconveniences caused"
Looks like we will just have to wait - thanks to everyone for keeping this situation updated. Come on TomTom - prove you can do it!