refused to take joining

Assalam O Alaikum!
I hope your kind honour will be fit and fine, sir it is submitted that I and other candidates applied for an appointment in autonomous body/department of the federal government of Pakistan, all the process like tests/interviews were completed and in the last HR Committee recommended the selected candidates for appointment. The offer letters were issued and received by some local persons of the city and on the same day the higher authority was transferred and new officer posted and refused to take joining from them. The newly posted officer has written a letter to call the board meeting in which the proposal for cancellation of the present recruitment process will be presented. The issue of cancellation is that the provincial/regional quota is calculated properly, although the Establishment has approved and issued NOC to the Department to advertise the advertisement.
Sir, my request is that although the selection HR committee has finalized the process and recommended for appointment, then can it be cancelled by a newly posted officer? and what can we do in this regards??