A few things come to mind: You say that 'for almost 6 six months' if that is the case then surely they did not contact you until after 11/2/00 which means they only have 6 years to chase you. If the repossession was older than that and no contact made until after 11/2/00 then that is the end of the matter.(posted 8545 days ago)If not, you are fully entitled to see the valuations whether or not it is the company policy. Also, ask them about the Statutary Instruments that you shpould have got when the property was repossessed - the details are on this site. If the house was repossessed without your knowledge ask if a court order was obtained. As well as the valuations have you got a FULL breakdown of the accounbt detailing ALL costs. If not get one - again you are entitled to it. You will probably find that most of the figures are far too high, ask for full justification and receipts/invoices.
Basically, make them prove to you that the debt is justifiable and that everything was done in fairness to all parties. Do not admit liability make them prove you are liable, ask them to show you the documents that say you are. If they refuse or ignore things ask again and keep asking until you are 'fully satisfied'.
Also, have you been told that 50% of the debt is now written off by the Abbey? Hopefully some of what I have said will help, others may be able to add more.
Keep fighting, they are trying to wear you down so don't let them