The most pathetic service I have ever used

My scientific samples should have been delivered in 24 hours to our lab by TNT and this company just simply forgot to fetch them from the field where we worked!!!! Samples needs cooling and being outside of the lab for so long changes their chemical composition. I have been waiting for my samples for 3-4 days. I even do not understand how is it possible that such an important service does not operate at weekends??