This is not your fault- the new manager should have reviewed your contract. Hopefully, your recruiter can work it out for you. Because it is in your contract, denying you your promised time off would be grounds for you to break your contract, if you choose to. I would tread very carefully in this situation, because if you do end up getting the week off, your manager could be pissed off, and could make the rest of your time there miserable.