Under the TUPE regulations, employees employed by the previous employer when the undertaking changes hands automatically become employees of the new employer on the same terms and conditions. It is as if their contracts of employment had originally been made with the new employer. Thus employees’ continuity of employment is preserved, as are their terms and conditions of employment under their contracts of employment (except for certain occupational pension rights).
As you have now agreed to new T & C's, i.e. more hours and less holidays, you should request a new contract is issued.
Also, do your new holidays comply with the European Working Time Directive in respect of holidays granted, i.e. 5.6 weeks or pro rata if working part time?