Sigmasoft interview questions

I had cleared multiple technical and HR rounds of discussions. Post clearing all interviews, the HR team asked for a long list of documents and we had provided the same. Prior to providing the documents, we had the HR discussion on all points including the role budget and the HR team agreed to the candidate expectations. On providing all the documents, the next day the HR team informed there is a budget constraint and mentioned they will not be releasing the Offer Letter. The HR team and management is directed to stop such unprofessional practices. Also, convey the role budget information to the candidate prior to scheduling interviews and not waste candidate's and company's time. Moreover, if a budget constraint persists, there is no need to ask for interviews, candidate documents etc.