Pelikal,
Honestly, my suggestion ?
Its BT, and its a BT Retail Consumer service, so you're really at the bottom of the pits.
If I were you, don't waste your time, I'd just escalate it to the so called "Chairman's Office" and be done with it. Its quite obvious in true BT style that all these suggestions of extra RAM and the desktop having something to do with the price of eggs are all utter bull.
Doesn't actually get anywhere near the Chairman, they've got a HLE (High Level Escalations) team that deals with all the incompetence. To give them their due, the guys in HLE are quite good and have sufficient ass-kicking authority to get things done.
Check your PMs for a pointer in the right direction.