1) Is it a car loan or is it a HP agreement? If it's a HP agreement, they are definitely right.
2)Check that it is a variable rate loan. Most car loans are actually fixed rate loans.
3) a lender can't charge a penalty for early repayment of a variable rate mortgage. But I don't think that applies to normal loans. Check the Consumer Credit Act - it's easy to read.
4) Get out the loan agreement and check that out in detail. See what that says.
5) Ask them for a written statement of the early redemption calculation. Don't take their word on the phone.
6) In theory, the EBS is a mutual and might make a represenation on your behalf.
7) Obviously, if they are charging you the interest up front, you should not pay off the loan. Put the money on deposit instead.