Telephone support hours - change in contract?!

[#1]

Surely thats a major change in our contract, us choosing a provider with the security of a 24/7 contact centre for any issues, and then they change that?!
Does anyone agree or know if this is being treated as a change in contract?!
http://www.thinkbroadband.com/news/7015-telephone-support-hours-changing-at-plusnet.html

[#2]

mod:note
already under discussion here https://community.plus.net/forum/index.php/topic,140849.0.html