If Xmas was the only period throughout the financial year that you were unable to take leave then you have no real complaint. It is fairly common for companies to block leave applications for busy periods - quite often for more than just the Xmas period. If you were able to book leave during all other months throughout the year, then it's bad planning on your part (sorry to sound blunt but it is your responsibility to use your leave). Some companies will allow staff to carry over leave and you could try to negotiate a deal. However, this is at the discretion of the company and is not a legal right. Having said that, if you have seven days left to take by the end of this month - your employers should make every effort for you to use this if you make them aware.