Hi laura, there is another thread that was posted in the last few days about a similar thing - a mobile phone debt accrued when the person was 17 and now 5 years on a debt collection agency was asking for the money. The consensus on that thread was that althought he debt was accrued when she was 17, she is now an adult, and the adult responsible thing to do is to repay, rather than trying to worm out of it. Its not the bank's fault they "let you take the money" it's your fault for taking money that didn't belong to you, so now you have to pay up.
The consequences of not paying up will haunt you throughout your life. At 22 you might not be able to imagine the sorts of things it could affect, so i will tell you my experiences:
mr bednobs got into debt when he was young and stupid, to the tune of around 2000 pounds. He "dropped out" of society, to avoid paying and burried his head in the sand. years later when i met him i knew he had a secret, and it nearly drove us apart. the debt collection agaencies were after him, and he found it difficult to tell me. He went through a period where he couldn't sleep, felt very unel and it was on his mind all the time. Eventually we tackeled it together. Later still, it was hard for us to get a mortgage - so i was being punished too for his past indiscretions.
recently he applied for his dream job which because of the secret nature of where he is working he had to have extensive background checks into his life, my life, his parent, siblings etc (so that he cant be blackmailed into revealing state secrets) These past debts came up in this background checking and there was a period where it was uncertain if it would prevent him getting the job, and this is nearly 20 years later, so it's still having reprecussions now!