I thought I put an update as to what happened with this but I guess I didn't, and feel a bit guilty now that it isn't here. After much ringing up Toshiba UK and insisting to speak to someone 'higher up', eventually I got past customer service and the arrogant and quite rude manager, and spoke to someone at head-office.
The gentleman at head-office couldn't have been more different to his colleagues at "customer service" (sic). Straight away he offered me the chance to buy a new warranty and get my laptop fixed under that. He agreed that the cost to get it fixed was very high considering how long I'd had it. As soon as he cleared that, my laptop was returned in under a week in perfect working order.
That was one occasion it was definitely worth the battle to speak to the right person. It changed my opinion of Toshiba, just not my views on their CS team.
