Loan amount wrong on credit report - Advice???

Giminy

Having taken out a £25k loan with the AA I was notified of a change in my credit report and went to have a look only to find that the AA had enterered the amount of the loan amount as over £42k.
I instantly phoned the AA only to be told that this was normal (they had included all the interest for the full period of the loan). I queried this with them saying that in fact I did not owe them that money now and therefore the figures were incorrect, and if anyone else looked at my credit report they would think I had much more debt than I do. They advised that this was the normal way loans are shown on credit reports.
Having had loans in the past I have never had this.... surely it can't be right as I do not owe the full 42K now?
Please help as I really want to challenge this if it is incorrect.
Thank you.