I paid late once because I mis-calculated how long a payment would take to clear over the new year period. I phoned the card company and they refunded the late fee but not the interest. Seemed pretty fair to me. So yes, give them a ring.
I also then setup a direct debit for the minimum payment. You will want to check how your card company handles extra payments when a direct debit exists. Most of my cards still take the minimum payment so you have to work out how much to pay to clear the card and not end up with them owing you. Barclaycard on the other hand stop the direct debit if you pay ANYTHING in the statement period, even if the amount you paid was less than the minimum.