Hours of work

[fairywings]

My friend has worked with me since september. since starting he has worked 6 hours on a sunday and 8 hours on a tuesday. however when the pay has been put through he is paid 4.5 contracted hours and the rest as overtime. his contract was mistakenly printed on a fixed term contract stating 6 hours. the company are now telling him he can no longer work tuesdays and will only be paid 4.5 hours for his holiday. can they do this as he has worked these hours for over 13 weeks and his contract is incorrect. also can they take hours off u with this little notice?