Halifax Interest Claim - how much?

wigglebear

I have just been made redundant so am finally getting round to claiming my bank fees (yes, I know, I should have done it ages ago) from the Halifax and have been collecting up the letters from the bank saying how much they have charged me as well as hunting all of the statements.

I have noticed that there appear to be 2 fees - one of them is the straight amount (which does seem to change but is usually £35 or £30 and even a couple of £39). Then there is the unauthorised overdraft fee of £28, but that doesn't always seem to be applied. I understand about those two bits and have totted them up - gulp, does it come to a lot - using the calculator on this site to work out the interest of 8% on them.

But then on some of the letters there is also a paragraph which says:

"We will also charge you debit interest on any overdraft. The monthly unauthorised interest rate will apply to the amount which is in excess of you agreed overdraft limit"

Does anyone know if it is possible to claim this 'fee' back too? On the months that it has been applied it seems to be about £30 and they can really mount up?