First you should contact the module/course coordinator. Their feedback may help to explain your marks.
If you are still unhappy, you have the following options:
Please note that you cannot take any of these four actions based on the provisional results of Semester 1 exams (released in February), which are subject to change. You must wait until all Semester 1 and 2 results have been approved by an examination board (in June/July for most students, or in August/September for supplemental exams).
If you cannot find the answer to your question, or if you need additional support, contact us: