Safexpress — Parcel exchanged. No definite reply from company

I booked a courier service from mumbai to agra which was supposes to be delivered on 8th april instead I received another package . It had the correct way-bill no. sticker but the package was different.
I've raised the issue and it's been more than week. I've called the mumbai branch, agra branch and the customer care but there is no definite reply from their end. The staff is not taking any responsibility and even after telling them the package is time-sensitive, the staff is blaming each other for the exchange. I am a student and have my Cfa exam in May. The parcel contained all my books and notes along with other expensive items. It was a year worth of my hard-work and now i will have to defer the exams which would cost me an extra ₹50, 000 .
I want the company to take responsibility and take measures to resolve my issue at the earliest.
Apart from the monetary loss it would also jeopardise my future which cannot be compensated.