Hi - I ended up renewing with Plusnet again - but told the (online) agent that I would like it noted that the only reason for staying (after all these years) with Plus was because of a) the UK based and professional customer service (nothing against overseas based service but Plusnet seems to definitely train its staff better) and b) this really great and well monitored forum.
Hope this hint - 'Don't let an idiot BT exec with a spreadsheet wreck it all' - does make it to someone somewhere...