DTDC Courier & Cargo — irresponsible service and very rude staff behavior

From university they sent me original certificates through dtdc courier, tracking no is k31564463 on 17th may 2019
But without contacting me, courier service returned my document. When my cousin went to office for enquiry the courier staff mr. Naveen spoke very rudely with her and my cousin called me from there and with me also talking with very harsh words and at least he don’t have little courtesy also how to talk with customer and disconnected the call, very disappointed with dtdc agent. Pls look into the matter.