Plagiarism again!! This time is worse as it happens in Make-good Assignment

I had been working hard to revise the students' mid-term grade through the analysis of the Make-good Assignment. I REALLY READ what they wrote because I tried to give as many marks as I can. However, I feel really sad when I discovered plagiarism among the students. Plagiarism (meniru) is a SERIOUS academic offence. Apart from give ZERO score to both parties who involved, I am considering take disciplinary action against both parties.

When I re-checked the Make-good Assignment submission all-over again, I discovered another pair of problematic students. I feel really sad and upset... My intention of giving this make-good assignment is to help weak students to survive, but I never thought such good deed would turn into a sour experience. I rather spend time doing other works then checking whether there are any other student who plagiarize or not. Really wasting my precious time...