Cheesecake, it looks as though you are still entitled to standard holiday (however many days were agreed in your formal contract. But not to any 'Additional' paid holiday.
If you needed to take the days off for personal reasons, you would have to book them as part of your normal annual leave entitlement. Or, you could ask for unpaid holiday if you had used up all of your AL entitlement.
You should have some paid Annual Leave holiday entitlement as part of the main contract - this just states that additional can't be taken, unless it's unpaid.
Hope this helps :-) - sorry, I do 'whitter on' a bit