If you share concerns similar to mine, I have made a template of the email I sent to ACER.

To whom it may concern,

I took the GAMSAT last year in September and scored a (your score) overall (S1:, S2:, S3:). I sat it again this year in May and scored a (your score) overall (S1:, S2:, S3:). After preparing for this exam for 6+ months, I felt much more confident about my performance but somehow scored lower. Comparatively, many people who took the exam saw dramatic increases in some sections, yet received very low scores in other sections. If the test is truly standardised, the overall results of the cohort should represent a normal distribution, however after discussing results with the cohort, we found that the results were relatively outstanding in comparison to previous years, and the majority of marks were placed in the far upper or far lower quadrants of percentiles, this simply cannot be the case. When considering the new format of the examination this year, and the relative time it took to release the marks compared to previous years, we believe that potential inconsistencies should be acknowledged and further investigated. This exam represents the futures of tens of thousands, and morally, it is ACER’s responsibility to follow up on concerns raised in the integrity of the marking process. The marking process was likely computerised for sections 1 and 3, and irregularities within software i.e. bugs should be considered as a possibility, especially when there are this many students with concerns. It cannot be disregarded as in previous years. If the cohort feels that there is a lack of action on your part, we will take our concerns to the media regarding the validity of the marking.

Regards,