You may need specialist advice but you can (and should) negotiate with Barclaycard/the debt recovery company.
Ultimately, Barclaycard will have to take you to the small claims court to get the money back. They can't put you in prison or anything. Unfortunately, your credit rating will almost certainly have been severely affected by this and I would guess that a county court judgement won't actually make things that much worse. If you end up in court you will be sent a form asking you to list your income and outgoings and the court will use this to decide how much you can afford to pay out.
To negotiate with the debt recovery company you need to make it worth their while not to go to court, ie offer them what they would get if they went to court. They have to pay to take you to court. So draw up a list of your income and outgoings, look at it from their eyes to see if it is reasonable (eg, pocket money generally isn't thought reasonable) and work out what you can afford to offer each month.
HOWEVER, you need to be very careful because of the length of time you have owed them the money. If there has been no contact for 6 years then the Limitation Act kicks in. This stops them from going to court to get the debt back. Because they cannot go to court, they have no sanction over you and so effectively they cannot get the money back. You need specialist advice here to see if this applies in your situation.
You probably do owe the company the interest on this money, providing its interest you signed up for, etc. However, remember that they want some sort of settlement for this debt. On their side they have the ultimate sanction of a CCJ. They will probably only go down this route if its worth it for them, including the cost of going to court (paying staff as well as the court fees).
If you can offer more than what they are suggesting, then it may be worth getting specialist advice although you're probably better off just paying what they suggest.
I think that the CAB probably gave you this advice to see if you could get to 6 years without them contacting you. But a year really isn't that long to go without contact if you have moved house, etc. I certainly wouldn't assume it had been written off under these circumstances. I am suprised that they didn't talk you through the ranmifications of ignoring the debt-that was probably negligent and you could make a complaint, maybe even sue them for the interest! Waiting to see if the company will forget for 6 years is always a gamble and seldom pays off, it is an option and they were right to make you aware of it but for most people it will be a pretty bad option and you definately shouldn't have been told to do this without having all this explained to you. In fact, you shouldn't have been told to do anything, you should have been talked through all options and given support if avalible with your preferred course of action. Thats generally true of any advice centre.
There's not much point going to a solicitor as few of them are debt specialists-they tend to dabble a bit on the side. Apart from the 6 year thing, this isn't really a legal issue anyway, its a question of experience with negotiating with creditors, which an advice agency will have much more of than a solicitor. You might need to see a specialist or a caseworker. All CABx are separate organisations, so you could go to a different CAB and you really shouldn't get this same dud advice again. Explain the advice you had last time-you'll probably find they treat you very carefully. Alternatively look on the Money Advice Trust (www.moneyadvicetrust.org/) for more organisations that can help. Don't pay for advice either or pay anyone to manage this debt-these organisations are cowboys. Look for an organisation with a Legal Aid franchise in debt/money advice, as they have to comply with certain standards (eg regular staff training for the franchised workers). If they are an advice agency, they will not normally charge you for the advice even if you do not qualify for legal aid.
The bottom line however is that they cannot do anything more to you than a CCJ. They cannot take your house away, or put you in prison. Compared to the amounts they are used to dealing with, £800 is hardly anything (I know that's not much consolation when you have to pay it back). A CCJ will only damage your credit rating a little bit more.
Incidentally, it is unlikely to happen but if baliffs come round to your house, do not let them in under any circumstances as they then gain the right to enter your house using force at any time to settle the debt.
Also try www.adviceguide.org.uk, which is the national association of CABs website, it has some good stuff about debt. You were given bad advice by the CAB you went to but if you can, don't let that put you off going to a different one or another advice centre.
But go and see a specialist-I do work in the advice sector but this isn't the area I specialise in.
, although I can try to clarify anything if you want. I'm not trying to push the CAB when you've had such bad advice but they do have bureaux in most towns and generally, because the advice is nationally monitored, you should get accurate advice, I think you just drew a very bad card.
Remember, you are trying to strike a bargain with them, its worth haggling a bit, just use common sense (but do see someone first because its 6 years since the debt was taken out).
Good luck!