The law requires that you must be provided with a 'written statement of employment particulars' (which isn't quite the same as a 'contract'):
http://www.direct.gov...dConditions/DG_175704
If any of those particulars change you should be provided with a new statement.
The only statutory requirement in relation to holidays is that employees (who work 5 days per week) must receive 28 days paid holiday. The employer is free to choose when those holidays are taken. (If an employee would normally work on the day of the week when Christmas Day occurs, the employer may insist that he/she works on Christmas Day at their normal pay rate. Similarly, as long as employees receive 28 days paid holiday per year, an employer can insist that they work on any other public holiday, including the Royal Wedding date).
However your contract (which is unusually generous) appears to give you additional rights. If it specifically states that you'll be paid to off work on all public holidays (plus on 30 additional days) then it would seem that you're correct in your view that you should receive a day's paid holiday.
Call the ACAS helpline for further advice:
http://www.acas.org.u...x.aspx?articleid=2042
Chris