PS got a letter from them with a claim reference number, can send on if you wish

Got a £30 bank charge for being £25 over my OD, really miffed, so phoned and complained! Very nice chap I spoke to and said that he will register my claim and if the OFT find against the banks then they will refund all my charges! Are barclays telling me lies? As a matter of interset i asked "how much have have I paid?" reply "let me see, well its £550 in the last 12 months" at the flick of his buttom/cursor. Is this Kosher and will they refund this or am I being naive?