Ok here is an image so you know what i am on about

So Fibre has become available in our neck of the woods so i decided to upgrade my plan.

Unfortunately when upgrading me plan it charges me more than the offer (i am sure this happened last time too)

The offer for 12 months on fibre 100 is 84.95 however we get charged 89.95 when trying to upgrade our existing plan, if i was being charged that much i may as well get the 24month plan that comes with an appleTV, in fact I would have preferred that plan, but it seems we can't get it despite the terms and conditions saying that it is available on NEW fibre 100 connections which we would be?

Any ideas, should i try the call centre and is there normally much of a wait in the queue?