Trying to upgrade to Sky Cinema but price difference

[RhysEvans93]

So I've just seen an advert on the website advertising Sky Cinema at £8 a month for 18 months, which seems like a good deal! 

However, when I click through, it suddenly changes to £10 a month.

What's going on? Is there any way to actually get the advertised offer?

 

[westland16]

There are two message threads about this already, with no resolution from Sky.