Goldfish - Interest charged on 0% Balance Transfer

Ivy_Bank

I wonder if anyone can advise me, please?

On 18/07/07, I transfered £2 000 to my Goldfish card, at a promotional interest rate of 0%, paying an arragement fee of £50.

My first payment was due on the 24th August. I have had my Goldfish account for years, and had always paid by direct debit, so assumed I was covered for repayments, but I rang to double check on 24th August, and was told that I didn't have a direct debit in place - my bank must have cancelled it as it hadn't been used for a while. I then made my payment (on the 24th) by debit card, and arranged for a new direct debit to be set up. The Goldfish advisor told me that a late fee had been put on my account, but that she would reverse it. I asked if the late fee would affect my account, and was told that as long as my future direct debits were made correctly, the account would work as it should from then on.
On my September statement transactions for August 24th were listed as:
LATE FEE £12
DEBIT CARD PAYMENT £41 CR
AUTOMATIC LATE FEE REVERSAL £12 CR
FINANCE RATE CHANGED TODAY £0
INTEREST £9.14
I assumed this meant that, as I had been advised, my promotional balance transfer was back on track.
It wasn't until I was catching up with my last year's accounts, that I found that I have been charged Goldfish's top interest on all my balance since Aug 24th.
I wrote to Goldfish, asking them to check this, and refund the interest overpaid.
I was phoned by one of their advisors, who said that I should have let them know earlier, as it is now too late to do anything about it.
I told them that I hadn't checked any further back then, as I'd seen they had refunded the late fee as promised, and assumed that the rest of the transfer details would be honoured, as promised.
I was told that I should never assume, but always check my statement, and get in touch if I needed to query anything, again, it was too late now (why?), they would not be refunding any interest to me and that was the end of the matter.
I wondered why I had not noticed the monthly interest charge, and realised that Goldfish have changed their monthly statement format. It used to be that all transactions were listed on the front page, which is where I would have noticed an interest charge. Now, the statement comes as a folded sheet. On the front page are listed only balances and limits, you now have to open and turn to page three for the list of transactions. That's cost me dearly.
I have now paid off the balance transfer, but I am very upset about the treatment I have had. Is there any way I can reclaim the interest charged? I feel I have been deceived and robbed. Or do I just cancel my Goldfish card, and write it off as a bad job?

I hope someone can advise me. Thanks for reading