Aramex Couriers — Return parcel not delivering

Two months back my cousin sent my medicines through Aramex courier to jeddah ksa, under AWB#[protected] aramex jeddah didn't deliver to me saying that one document is not included. At hyderabad the aramex agent SSS Courier services took all the documents 1.orignal invoice 2. Doctors prescription 3. PP copies and 4.Adhar card copy.
Now I don't know in this whose mistake is there and who is correct because both the side aramex is handling, since more than one month over my parcel returned from jeddah and lying at Blr. Aramex facility and they are not delivering to my cousin at hyd, and asking to pay duty on it Rs. 23, 000 thousand. I am confused why the duty is being charged and I am liable to pay when it is not my mistake this between aramex and his authrized agent to settle down this issue not me.
My medicines total cost is Rs. 28, 000 appr. And I paid Rs. 6, 400 as courier charges.
I request you to get my parcel back and also return my courier charges because the aramex didn't complete the service.