India Post — complaint about speed post delivery to mumbai

I have taken the speed post delivery service from Indian postal service- Nasik Road RMS on 7/1/19 at 8:50 pm, an important document for delivering some documents to apply for a govt. Job to Mumbai. At the time of payment when I asked then how much time it will take to go to destination, they told 2 working days. After that I was trying to track my parcel but there were no any updates available till 13th Jan. When I call to office to enquire about the online update, they assured me that the parcel may have been reached to it's destination on 10th Jan, also they told me that we have strike on 8th and 9th Jan so the website will update soon, and don't worry about your parcel. The last date of accepting that documents was 11th Jan till 5 pm. And on Monday 14th Jan the online update we're showing that the parcel has been received to postal office at morning around 8am and it was out for delivery on same day about 2pm. But because of last date was gone they refused to accept my documents. My vandidature has cancelled because of this. As it was a speed post we trust that it will deliver between 2-3 working days but it took 5 working days then what is the ease o[censored]sing speed post.
What should we do when such things are happening and just because some unprofessional working attitude I have pay for that rubbish thing.