Once your results are released you will be sent an email informing you they are available to view on SIMS.  Your interim transcript (results letter) will also be sent to your home address.  You are entitled to appeal against your results under specific grounds within 28 calendar days of these appearing on SIMS.  You cannot request that your work is re-marked and are not allowed to challenge the academic judgement of the assessors.

https://intranet.cardiff.ac.uk/students/your-study/exams-and-assessment/results/appeals