hi when i was 16 i opened a bank account with natwest and they said would you like an overdraft and i said no because my mum advised me not to.
As i was working at the time i had regular money going in the account till i lost my job and stopped using the account. Then when i was working again i had my money going in to my partners account and never used my old one again.
Until last year i had a letter off natwest saying i owe them the sum of £349.51 and it really puzzled me so i gave them a ring and they said i must of purchsed something and didnt have enough money in the bank and theye let me go over. this was 5years ago now and they bin charging me ridiculous amounts of money for bank charges. i no this is really confusing but im getting really stressed about it as i dont have any money pay them back, well theyve sold my dept to a place called capquest and they said today there soliciters will be getting intouch with me. ive made a appointment with citizen advice for wed.
luckily i recieved my old bank statments today, the bank did get intouch with me about the charges but i never recieved any of the letters because my mums husband at the time threw us out the house and he never forwarded our mail, and i pursued my account was 0 any way as i lost me job and didnt have alot of money going in any way, its really a long story and it seems like a long time ago now

Going to the CAB is a good idea. They will first of all help you to identify whether or not you actually owe this money. It will help if you can find out what caused the initial charge. Suggest you get hold of the bank statement that shows this transaction that caused you to go overdrawn.
How come the bank has let this debt mount up over several years without telling you?

See what the CAB says, they give very good advice.
If the facts are as you say, I don't see how the bank can hold you responsible, but banks are basically greedy in my long experience, and will say/threaten all sorts to try to make you pay. Don't worry too much about letters from solicitors - this is routine stuff with debt recovery. Solicitors are expensive, so the debt recovery firm won't use them unless they have to.
Don't ignore it, take good advice and try not to worry.