Trace back my document..tracing no: PE870 416 055ZA

I have posted my documents with an ordinary courier from Nelspruit to Durban last year,Somewhere around December 2017.Inside there was my Log Book for in-service training that I was doing in order for me to be graduated with my National Diploma in Surveying.Early this year I have sent my friend to collect this documents from the nearest post office but unfortunately they have delivered my documents to the wrong person.I have tried to sent emails or call them but unfortunately no one is helping me so that they can trace it back.If I don't get it,it means my in-service training was useless and its very hard to get a company and if I don't get it I wont graduate.