It's worse than that.
Apparently, CPS calls providers (Sky is the only one known to have done so so far) now have the option,
without telling their customers, of changing to WCA (Wholesale Calls Access) - which is the same as CPS except that is ignores the customer's attempt to override the default (CPS) programming of the BT exchange using prefixes like 1280 and 18185.
See
HERE.
Hi Heinz.
The link you gave is quite informative, and shows what a mess things seem to be in. Thanks for your post.
I don't know if the problem is just where I am or not, but I only see a red X where your avatar should be displayed.
If others cannot see it either, perhaps you would like to email me the pic you wish to use, and I will upload it to your profile for you.
Thanks again for starting to contribute here.