Tata Consultancy Services QA Engineer interview questions

Interview went well and i got the CTC break up email on next day and hr told we just need approvals for this CTC 2days later i got hr email for documents verification and everything is done. I have been waiting for offer letter and 1 week passed and i approached hr he told few approvals are pending so i patiently lisened to him . After more than a week i got email saying the client has changed their mind on requirements and they are unable to process my application. I didn't exepect this kind of process from TCS.. I have waited 3 weeks for just offer letter but the end i was very disappointed.