Can't view renewal offers online. Get an error message on every device I try.

Hi 

I have been having issues with editing my plan online for a while now. Whenever I try to view new offers or now look at my renewal offers I get a message that says "Oops! Looks like something's gone wrong. We couldn't find the page you're looking for." I've contacted support multiple times with this issue and every time they say we'll fix it or someone will be in contact. Yet every time they dont fix it and no one gets in contact. It's beyond a joke that it's been dragging on for the best part of 6 months now. 

This is the screen I get:

Anyone has any experience with this issue and know how to fix it?