No you aren't:
Holiday pay
For each week of their statutory leave entitlement workers are entitled to be paid a week's pay calculated in accordance with sections 221-224 of the Employment Rights Act 1996 as follows:
Workers with no normal working hours:
� If a worker has no normal working hours then a week's pay is the average pay received over the preceding 12 weeks. Any week for which no pay was due should be replaced by the last previous week for which pay was due.
The way I see it, you don't have any average pay as you haven't worked over the preceeding 12 weeks (or before that, probably). Why should they give you holiday pay when you aren't actually doing any work for them?
BTW, are you the person who's boyfriend works at the same hotel and were posting loads last year because they never gave you any hours? If so, I thought you had taken the advice that everyone gave, to give it up as a bad job and work elsewhere! It seems clear to me that they just don't want you to work there but just don't give you any hours rather than sack you.