Abbey Overdraft from 2001, need help!

Hi, this is my first post here which i suppose is pretty obvious if theres a post count on the left, ANYWAY.

First a little background:

Back in 2001 I was preparing to go to University so when i showed abbey proof of my acceptance in the summer they upgraded my account to a Student account with an Overdraft of £1000, Being the idiot i was back then I assumed i would have plenty money from my student loan and so proceeded to spend spend spend. I didnt receive my student loan untill december and when i did it was only enough to pay for my student lodgings so i ran into some trouble. Getting down to it, I basically ran out of money and had an overdraft at just over £1000, I was unable to get a part time job as i left it so late and could not sort myself out. So during that time I asked for help from my parents or Girlfriend who could only give me around £40 every so often, what ended up happening was, My parents would put £40 into my account which would take me to £980 then Abbey would charge me for being over the overdraft limit which was a charge of around £30+ which obviously took me back over the overdraft limit again, then another amount would go in and bring me back down under £1000 just for abbey to charge me again and i would be back over. This happened 3 or 4 times and eventually i gave up as they were eating the only money i was able to get that i needed to get food.

Right thats the background out of the way, Basically i stopped paying, Abbey got angry when i told them i had no money to give them, I had a couple of phone calls with some people who just didnt want to listen to me not having any money but seemed to enjoy listening to me squirm on the end of the phone. I just put my head in the sand as i hadnt a clue what to do being that id never been in debt before and was afraid to tell the parents. I did try to pay when i had money to give, I believe 1st credit had the debt for a bit and I paid them a couple of times while employed but eventually stopped paying again as I became unemployed and couldnt afford it. I ended up getting letters from 1st Credit in which they would bump the cost back up.

I havent heard anything for quite some time. Obviously its now 2008 and I have received a letter through the door from ScotCall Debt Collecting services claiming I owe £1021.16 stating the creditor was formerly Abbey, It also claims they have sent a letter before this which I never received as this is the first letter for quite some time. It was probably around 2002 when abbey closed my account and started chasing the debt so we're talking 5-6 years here. I am unemployed currently and in the middle of applying to join the police. Basically I plan on contacting Scotcall, I was thinking of doing it by letter and putting it on recorded delivery as I cant say I fancy talking to any more people on the phone who have attitude problems and I want something I can fall back on as proof. I was wondering if theres anything I can send them that may force them to prove I actually owe them this debt seeing as I haven't heard anything for such a long time. Im sure I've heard of people using a letter to send however I'm unable to remember what it was and thought it would be best to explain my situation fully and get some advice on it instead of searching, finding the info and going on alone.

Also, I'm not trying to get out of this debt, I fully accept responsibility for running up the debt in the first place but seeing as its been such a long time since I heard anything from anyone about this debt I'm wondering whether I actually still owe this debt. I'm aware that there may be some difference between Scotland and England when it comes to law so just in case this helps, I live in Scotland.

Any help you can give would be much appreciated, Please make sure you provide any necessary links that might help me.

P.S please excuse any spelling mistakes etc, I haven't enough time to thoroughly look this over and I've rushed through this.