UPDATE EVERYONE:-
This evening, I took my original letter, in person to my local Tesco store.
I asked to see the manager to hand it to her personally, she asked the customer service lady, on the phone, what I wanted to speak to her about.
She came down, new exactly who I had spoke to, and then asked me if I'd be happy to come to her office.
We went up, and she apoligized for the attitiude of her staff and said that she will be personally investigating.
I handed her my letter, she read through and told me how astonished she was by the way I had been treated, I then informed her that I had emailed the letter to officers at Trading Standards who were investigating.
She called up Acer from her office, demanded to know why they didnt offer to repair it when it was manufactured in August 05.
The bloke on the phone passed the call onto his boss at Acer, who apoligized to me and offered to have my laptop collected first thing tomorrow, repaired, and returned within 10 days. He also said that the usual turn around time was 15-20 working days but assured me that he'd personally see to it and make sure my repair was speeded up.
Tesco have offered me an apology letter from the staff involved, and a set of £50's worth of vouchers to use against non food items.
So my laptop is being picked up tomorrow.
Thank God

. I was missing her already

.
Thanks for all your suggestions.
Kind regards,
(a happy) Tom3131.
