Hi I had similar experience last year, I called them and was honest like you as I thought there could be an error but they said all was correct and nothing more come of it, so don't worry as you have been honest and called them which is probably logged.

Hi, am pleased to see I am not alone with these excessive, unjustifiable charges. I am a mother of two children under the age of 5 and when I had a few spare minutes the other night after watching the Trevor Mcdonald programme regarding Bank Charges I decided to dig out 6 years worth of Statements (Halifax). To my horror the total came to about £1,900 !!! I am so glad I saw the programme as these charges probably would have been put to the back of my mind as I normally have a 3 year old clinging to my every move but student, employee or housewife I am going to fight them every inch of the way (after the school run).